If you have room for a shaft drive, go with that. I have read many a post and blog describing problems with saildrives, all of which have been mentioned in this thread. To eliminate vibration, go with an Aquadrive system. Aquadrive
The fellow who bought my old boat put in a bigger engine, and installed an Aquadrive system. I couldn't tell when the engine was running, even though all that was between me and it was a piece of plywood
. From a design standpoint, the benefit / drawback of a saildrive
is that the engines are mounted further aft. This gives more interior
room for the accommodation but has the potential of exacerbating pitching, and depressing the stern. If you plan on doing a lot of motoring, I wouldn't use a super lightweight engine like a Yanmar. I'd go with a 4 cylinder Deere.