For water sports, I'd get at least 115 HP.
Check for soft spots on the floor. Also check the transom for rot. Rotted floor & stringers are time consuming and expensive to fix.
New upholstry is very expensive. If you are looking at a boat with weathered seats, get a quote on repair before you buy.
I/O's are a little more work to winterize, but to me that wouldn't be a deal breaker. I have a boat with a 350 MAG. All I have to do to drain the block is pull four plugs. Takes less than 5 minutes. In my experience, they are more reliable than the older 2 stroke outboards, and less expensive to run since you aren't having to spend $ on oil everytime you fill the tank.
If you go with an I/O, I'd stick with MerCruiser 1st, then Volvo. It's more difficult to find parts & service for an OMC.
I agree to stay away from the earlier year Force engines. Later, they were purchased by Mercury. I have a 50 HP Force by Mercury on my 1998 Smokercraft, and it has been very reliable.
In that price range, I'd consider the following:
1989 Sea Ray
Kind of slim pickings right now.