When looking at the plane in question, there will most likely be a range given as to what engine sizes it will handle. Once you make a few decisions on planes, post a question on RCU giving the exact name/size of your engine and the plane(s) you are thinking about and get opinions on what others are doing as this will help you allot on getting a good engine/plane match.

The other thing is tell us exactly what engine and ask what would be a good plane based on what you want to do with it (aerobatics, sport flying, etc...).