On my last boat, a ketch of similar displacement to a Mango, I installed an Octopus LAR driven with a Simrad AC42 and was very pleased. Octopus makes a number of different types of drives that all seem to have a good reputation.
I would definitely NOT use a drive that was marginally rated for the boat's displacement for offshore sailing. They can work hard and long, and one that was working near the high end of its power output a lot is certainly going to have a shorter life.
On Harmonie my primary pilot is the AC42 driving the Raymarine linear drive.
Hilton Head Island, SC