If it's hydraulic I think you could get away with any good wheel autopilot.

If it's cable a wheel pilot won't be strong enough and a dedicated, under deck auto pilot is needed.

I know there are some that don't like Raymarine but our Raymarine smartpilot has worked in all conditions singing a song while it's doing it. Corkscrewing downwind in 30 knots and 10' confused seas from 3 directions. If it wasn't for that autopilot I think that night would have gotten the better of me. Our boat is about the same displacement as yours 40,000 lb+. Never had a problem except for when the computer that controls it went out. It was 12 years old and couldn't be repaired but Raymarine offered a new, current model for 1/2 price. I thought that was a good gesture and went for it..

A dedicated under deck system with compass, corepack, drive unit and control head will cost in the neighborhood of $2,000.00 but driving with no autopilot really sucks, We only did it for 3 days and were thinking of installing a second redundant system.

I think a lot depends on what other electronics are installed. If you're starting from scratch anything goes but if you have wind instruments that you're happy with and aren't too old you might want to explore the same brand as the interface between them all might be better.

I was looking at a Furuno but decided on the replacement Raymarine because of the $$$ and offer they gave me.

I'm surprised you got so far with only the windvane.