For 20 years I have used one of those ray marine sailboat wheel pilots on my W30 Puffin. It works just fine because, as you said,, a W30 hull shape is the same as a full keel sailboat. I remember when I purchased it, the tech rep at Raymarine was adamant that a sailboat autopilot would not work on a motor boat. He did not understand the basics.
I do not have the electronics going to an hydraulic pump. It activates a small motor that turns a wheel that is clamped to the lower helm wheel. The drawback to this system is that I cannot manually take over steering if I am up on the flying bridge I have to go into the cabin and unclamp the wheel mechanism to take over manually.
If you use the electronics to power a hydraulic pump then you don’t have that problem. However, the amplifier than turns that small motor may not be adequate to turn a hydraulic pump.
Willard 40 -Lilliana-Sea of Cortez, Mexico
Willard 30- Puffin- SE Alaska
Tiffany Jayne 34-sailboat- Dancer- SF Bay