We bought an 18' Bayliner this summer, we have a jeep and did not want to get a big truck so boat size and weight was limited to the towing capacity of our jeep, max tow 3,500lbs.
Boat has a 115hp outboard, we ski behind it the wife can get up on a slalom ski no problem. I weight 185 and its a struggle, currently running a 16p 3 blade at Lake Powell 3,600' ABSL and I hit close to max rpm's with that prop. I can run wide open 5800rpm @ 38mph max rpm is 6000.
Considering a 15p 4 blade prop for better acceleration to get me up quicker and easier, not to concerned about losing a little top end speed.