I hope to soon buy a boat and plan to budget for new electronics. I won't be able to afford the top of the line, more likely the basic entry level, but I plan to budget enough to equip the boat with a quality integrated system starting with GPS, chartplotter, VHF with AIS, and later add radar.

What manufacturer do people like the best?

Garmin, Raymarine, Furuno, Simrad, Lowrance, Standard, B&G? Am I forgetting any?

Since I will be spending a lot of money, I want to have a system that stands a chance of being current for a while and is backed by good customer and technical service and repair.

Doesn't matter what brand you use, they all are pretty reliable regardless of what gets written and will last the same. The best deal is always to get a "package" that is already bundled together.

You are missing B&G which is the Sailing brand from Navico (Simrad is big power, Lowrance is little power) As noted above, big 4 are pretty competitive, look at features and at fundamentals.

Most important is a reliable depth indicator (what you can't see), get a good handheld GPS and VHF (combo are avail) and then fit out with speed, wind, chartplotter etc.

Some inputs of what your sailing area/style and vessel would help. You mention AIS on a VHF, so presumably you have commercial traffic. Taking "midwesterner" to indicate likely Great Lake or smaller, here's a nice product line that you could put on a moderate boat for casual sailing and then upgrade about as far as you cared to.
http://www.bandg.com/en-US/Product-Groups/Triton/

I run a 40 ft Yawl shorthanded on SFBay and have a different fit out for my club racing and delta/offshore cruising than I would with a 20 ft trailer sailor on a lake.
(I run the B&G H5000 at "Hercules" software & Sensor level, Zeus2 plotter with 4G Radar & scanning sonars but lets just say that's a slight overkill due to personal preferences)

You might not ever want an autopilot, nor a performance processor to calculate target speed and wind angles, but its nice to know its feasible.

Midwesterner only reflects where I live currently. I soon hope to semi-retire and start sailing around the Chesapeake Bay and Pamlico River area and coastal cruising up and down the East Coast.
A current boat on the top of my list has an old Furuno radar that still works.
I probably will start with a plotter and VHF AIS. I have a handheld sportsman's GPS for backup and I have a tablet/laptop with an external USB GPS antenna that I intend to load some mapping program on.

Thanks.

Paging MaineSail...

The glaring missing company is NKE. easily the best autopilots around today. They are on the high end price wise so you may not want to spend the money, but it would be a good idea to price their kit out.

So given you plan to coastal cruise in areas that do have Fog, Radar is pretty essential unless you can hang out till it clears.

Lets assume that you have a 30-40 ft boat if you plan to coastal cruise and candidates have Radar.
A single merged speed, depth, temperature transducer is adequate, put it where you can access to clean the inner core.

GPS with integral heading sensors are < $300 and many of the chart plotters have them built in. Note that most of the low end chart plotters won't display radar as they don't have ethernet, so do check.

A good 6-9 axis heading sensor will be a worthy investment, it allows the radar to overlay and the autopilot to track.

Having the radar integrated with the chartplotter is damn handy, and the AIS displayed as well, so an integrated system will be a major choice: Note that most of the new stuff runs both ethernet and NMEA 2000, and you will have some significant wiring to think through.

With the advent of small Doppler radars this year, pretty much any older pulse radar is obsolete, and probably should not be a purchase decision, the 4G radar from Navico uses low power and has great short range performance, nice if you are coming through Woods Hole in the fog, but it loses a bit on the long end if you want to see storms more than 40 miles off.

You may want to use the ICW, in which case a forward scanning sonar is a nicety, but far from essential. We used an Interphase forward scan back in 2004 to explore anchorages up around Ingonish & Dingwall on the coast of Cape Breton Is where the charts are not that detailed and the locals make all sorts of interesting right angle turns in the inlet where there are no buoys.

The advantage that B&G brand brings vs the others, is it's focused on sailing, not a compromise with powerboating.
The Sailsteer display is very dense information that lets you look at one screen, and the effort in calibration is valuable if you want to get your boat sailing well.

That doesn't seem likely. I have read members' comments on this site where people say that there have been some companies like Garmin, that drop support of some of their units faster than some others. There was one discussion on here where one unit by Garmin had it's support dropped while new backstocked units were still being sold at clearance by dealers.

I've heard some varying reports of how easy or hard it is to get a hold of technical assistance at different companies.
That's the sort of information I'm looking for.
Thanks

Personally, I'd stay away from Raymarine. I've had some real issues with their gear from small yacht systems to the commercial grade stuff. Terrible support with techs who don't seem to be familiar with anything other than the same tech manuals I have available to me.
Garmin for the most part has been quite reliable and when not, their support staff are helpful and knowledgeable. Furuno is also an excellent company, though probably on the pricey side for just starting out. B&G were top of the line some years back, but my last encounter with the company (not their gear) left me feeling that they'd lost their edge.
I would highly recommend you purchase an autopilot. It will become your most reliable crew member who you will come to love. I'd put that way up there with a VHF, GPS and depth finder. Everything else can wait, unless you sail in fog. Then radar is a lot of help.
If I was looking to save money in the long run, I'd go with a chartplotter instead of a handheld GPS. Most come with built in charts for the US so you wouldn't need a lot of charts when you want to extend your cruising area. Saves plotting positions on a chart or maneuvering board.

Support: Lets just say that the manuals are generally lousy and the available free resources not much better.

I bought my sailing instruments from a level 3 dealer in SF Bay, and paid him list prices, for which I received great pre & post install support. I also bought an MFD from him at market price (75% of list) as it was not integral to the system and didn't require his knowledge of setup and calibration. (I've sailed for 50 yrs and 2 engineering degrees FWIW). I did my own installation, and he helped trouble shoot via email/phone/text before coming aboard and helping assess the system, and then coming out and doing the sea trial and calibration.

The manuals were usually written by somebody who might have known what they are doing, but who doesn't necessarily provide full answers and context, and often times are translated as well.

The B&G support guys are in Merrimack, NH, and have good product knowledge, and are willing to tell you what they don't know and to escalate questions and do the testing. Lets just say I had lots of rather specific questions, and they were generally patient, and where there was a reference showed me where to find the answers as well as providing them. Had I bought the stuff on the internet from a discount supplier, that's all I would have had.

There are (always) some bugs and necessary work arounds, and one piece (the pilot controller) has warranty failed, which on a system this complex is not terribly surprising, and acceptable. The factory sent a spare Radome when we had issues on signal propagation, which turned out to be the ethernet switch the level 3 guy provided, no questions asked or hassles. Panbo.com has an active forum on marine electronics and there are other online resources. They fix issues pretty quickly though, don't seem to be soliciting feature requests.

Charting code is a personal preference, there are Navionics, Jeppesen--> Navico Cmap and vendor proprietary formats.
some let you crowd source the depth data.

Suggestions: put together your budget for the next few years and figure that the fundamental pieces will be durable enough for the sensors to last decades. The processors and displays are probably a 5 yr replacement cycle and the wiring should go longer. I'm expecting to upgrade my new radar when the Doppler comes out, either as a software/module swap, or if needed a replacement of the interface module where the electronics live, hopefully not the rotating scanner, though that's not that much if I need to do so.