Like many of us...I got bored with the "trainer" very quickly. Although "trainers" can be very forgiving, it also means they are inherently less responsive. That being said...you actually have to be a better pilot to put a "trainer" trhough its paces than someone who can do a few aerobatic maneuvers with a tail-dragger. Let me explain. Performing a roll with a trainer requires coordination of all 3 axis...with a hotter plane ...you just bang the aileron left or right.

I have seen a member of our club take up an Avistar on its maiden flight and perform loops, rolls, inverted flight, spins, rolling circles, and a rolling loop. Many people cannot do those maneuvers or do them well. So there's a vote for an Avistar.

Personally, after a few flights on the trainer I bought a Funtana. On low rates its a *****-cat. Once you can land a trainer and "flare" ...you can land a Funtana. It will not take much abuse....but I learned every trick in the book in about 4 months time with a Funtana. Not a great recommended way probably...but it can be done.

Whatever you decide...mix in lots of simulator time and your son should be successful very quickly