Does anyone have a recommendation for a simple under the deck autopilot?

I have concluded that my Raymarine unit is beyond repair. Parts are no longer available and I don't want to be forced into upgrading all the other working electronics just to have compatibility with a new autopilot.

Although the old one was able to hold course based on wind direction and compass heading, I never  used the wind direction feature. I only used it as a convenient  second crew hand to hold the compass heading while I was  furling/ unfurling or trimming  the sails. 

Mounting a wheel drive autopilot hinders cockpit mobility. A stand alone, under the deck mounted to the quadrant would be ideal.