A 16ft Kalamath with a 35-40 horse engine is a pretty sound bet. It's a mass production boat, so there's lots around, and they're fairly cheap. Another thing you'll want to consider is whether or not you want a boat with a steering console or just tiller control. A steering console's a lot nicer, but not a nesecity, and can be in the way on smaller boats. Whatever you get, a galvanized trailer will probably be well worth the extra cost in the long run.