In the end you need to REALLY think through what you want to have installed. I learned the hard way with my C-80 purchase although everything worked extremely well (zero issues with my setup - but I probably do not run my
radar all that much because the screen size is so small).
But contemplate what all devices you want integrated into the system. For me - I want all the speed, wind, engine, tank levels,
radar etc to be accessible via a single screen and have the ability to remote that data to a PC or secondary display at the Nav station. If all you intend to do is run the
radar as standalone - be aware that normally stand alone units do not interface with PCs generally speaking. Much like
fish finder only units have no ability to share data across a network for the most part.
The concept of the newer devices is plug and play expansion much like a computer and USB devices. But, they still rely on a micro processor or what that call the "brain unit" to shuttle all that info around. The price points include the ability to expand much like a gaming pc is much more expensive than your $250 base desktop that all you can hope to do on it is surf the web. Hence the higher prices. And frankly this is one spot where you negotiate a entire system correctly the first time because there is no real market for second hand electronics when after the fact you decide it doesn't work for your needs. You can get upwards to a 20 - 30% off list prices if you approach the deal properly.
Spend some time on this issue, because just like your exhaustive search for a boat - the reason you did so was to find the boat that met the needs as well as price. The systems out today come in only three flavors "Cheap but can do the job", "moderately affordable but you'll still be limited", and "Expensive but worth every buck".
Like Hal - but not like Hal - I too also investigated Furono,
Garmin etc... for me even when I bought the C-80 I knew it wasn't going to do the big shabang (and I klnew when the card went swipe that I should of gotten E series instead) - but it would allow the PC to duplicate the main unit display. I was also constrained by available space...Now that I have the Barberis - the money spent on the more modular system - makes more sense because I can justify where and how I can use it. You have the space and room but maybe not the desire to spend the money on a more expansive system but you should reconsider that limitation because unlike any other system on your boat - it will be the one that gets most used especially during inclimate weather, and the flexibility you get down the road is in your favor...
Just random thoughts... good luck!