XS, Just have to add my 2 cents. I used a Merc
45 w/pump on my 16 Alumacraft. It was great, but with me back at the stern also, it sat too deep when not under way. Had waves come in over the stern in rough water. If I didn't eat so much or had been born to smaller sized parents this my not have been a problem. What did happen that was bad news however, is the transom began to push out or bulge. I bolted on a .19 inch thick aluminum plate and that stopped that. I don't know if it was too much trailering or too much power that caused the problem. If you plan on moving up in power, and hence bringing the motor weight to 200 lbs., I'd add a 40inch by 12+inch
plate on the back just to make sure you don't have the same problem.