You can use a garelick Fulton or panther brand motor mount probably up to 25-35 hp to be safe. Many smaller Hp mounts aren’t great durability. Use good backing plates for the washers and nuts. Measure carefully where you put it so it adjusts above and below the waterline. I got a used 9.9hp kicker with a 20” shaft. It works, but I’d probably prefer a smaller engine, when I tilt up, it’s right up against the stern rail. I don’t have to lower the bracket at all with 20” shaft just tilt the motor down so a smaller shaft might actually be better for me, but not going to overthink it. Would be nice to have a rig that links straight to your fuel source and steering if possible. I have to put a small 6gal fuel can out by the stern and use the tiller. I also have manual start and tilt but I’m not too fancy.