Absolutely agree with ifmdalvey on the EV series autopilots and the EVO heading sensor. The Hunter 40.5 is on the upper displacement limit for the EV200 system. I chose it as it was "within the displacement limit" albeit on the upper end and I am not planning on any long ocean transits (some offshore/nearshore but not across large expanses of ocean) The Type 1 drive is a little easier on the battery drain. The EV400 and Type 2 rotary drive is heftier but probably a little overkill for what I am doing. I imagine the Island Packet 37 displaces as much or more than our 40.5s. The EV200 is still a whole lot more robust than the wheel drive I had before. Your choice but I'm very happy with the EV200/Type 1 Rotary Drive and EVO sensor with the P70 control head. Everything interfaces seamlessly with my Raymarine a98 chartplotter.