darnnnel ,

What you should be looking for is a high-winger with a semi-symmetrical airfoil wing. The high-wing part will be of use when you dont lineup or level your landings correctly and the semi-symmetrical wing will allow the airplane to grow with you to some extent i.e. you can increase the throws later and fly the basic aerobatics with the same model. Also look for atleast about 60" in a 40 size model as it will offer the best stability.

In fact I did all my basic aerobatic training on my high wing trainer including loops, rolls, inverted, split-s, cuban-half-8, cuban-8s, vertical figure-8s, stall-turns and even spirals. Infact the only things I couldnt do was hover, snap and knife edge. That is the beauty of the semi-symmetrical wing: you can do all this and know that when you level out you can fly out of any trouble. I had a lot of trouble doing this with some collegues' planes that had flat bottoms.

I dont have much experience with the models you have listed but am told that the Avistar is more aerobatic capable. The LT-40 is good too, but I am concerned with it if it is a low winger.

Ameyam