I have a Simrad wheelpilot on my current boat and have been very impressed with it. Prior I was on a boat with the Raymarine system and found it had a much harder time keeping a course.
I'm not sure if the Simrad units are still in production, but if so, that is the way I would go if you don't want a quadrant steering solution.
I just bought a Raymarine X5 but didn't install it (too much snow here in Québec!).
There's not so much option for an above autopilot. The WP32 form Simrad is discontinued. The only model remaining in that category is the X5. The good point on the X5 is that you don't have to install that rudder sensor (like the S1).
I just finished and installed the x-5, so far so good, took me a bit to get it to talk to the wind vane but thats because it says in small letters that the wheel pilot can not talk via seatalk to other seatalk thru the daisy chained cables if it has power running through the same cable......so you need to run a separate cable in one side of the instruments that suplies 12v and another thru the other end that carries the signal (BTW this is three wire in total, shield, yellow and red...???)
It works like it should now though and so far so good.
i know TMI but anyone who has messed with it knows what I am saying and what a PIA it is..
South wind I would look at the displacement of your vessel first? might be a tad too close to maxed out on yours?
My old 1994 Autohelm control head died a couple of weeks ago. I bought the X5 and am happy with the improvements. It looks like the motor drive is about the same although the new wheel is slightly larger. It's also significantly quieter.
The big difference is the installation. Now you don't have to run those big 10ga power wires up to the control head then down to the drive motor. Instead there's a course computer with all the connections and you only need 16ga wire from the course computer to the motor. The control head is seatalk only.
The course computer has an integrated accelerometer like the Wii and is quite good at adjusting the wheel. I purposely set up an unbalanced boat in 20kt winds with too much genoa and the wheel pilot did a good job holding course when it took a lot of muscle on the wheel.
I also like the adjustable response feature. For long passages you can adjust the response down so it uses less power instead of holding a tight course.
No rudder sensor is necessary. It also has a Seatalk to NMEA converter integrated into course computer as well as NMEA 2000.
I was disappointed to have an unexpected expense and job of replacing the Autohelm but it's been a blessing in disguise as the new X5 is a big upgrade.
Here's a couple of pictures of the installation in my PSC 31 which is a pretty heavy boat - and mine is loaded down a few extra inches (about another 2400 lbs). The terminal strip is for AIS and NMEA which is not required for installation.
I don't recommend a wheel pilot for anyone unless it's a really small boat and your only planning river and small lake sailing. Why? Well I've been there and it cost me twice. I bought a wheel pilot a few years back based on the manufacturer's recommendation and it worked well in the Columbia River but as soon as I got out into the Pacific it slipped the belt and I hand steered all the rest of the way since to replace the belt required removal of the wheel. I now have a Ray Marine below decks hydraulic pilot and it works beautifully.
So, be careful and always buy a pilot recommended for a boat MUCH bigger than the one you have.