The RCM 40 (Global) and a Thunder Tiger .46 is a little better aerodynamically than many trainers (it will fly inverted and a tad faster than the Avistar, so you'll be less bored). We have LOTS of Avistars at our field and they are rugged and a good trainer.

A GP Big Stik would be a perfect second plane when you've mastered the trainer. The Big Stik has nice low speed handling but lifts her skirts at higher RPM.