what you might want to do as a starter float plane is look for the GWS Slow Stick. It is a great all around trainer plane. They are cheap and fly great on cheap Brushless power systems that you can find anywhere. Mate that up with a set of GWS floats ($12) and you are set. That way if you dunk it, the power system is cheap. I also believe that if not natively an aileron plane, it can be equipped with them easily.
Curtis