RE: Second Plane Advice
Nope,
Save the warbirds for the thrid or typically fourth plane.
Fly the guts out of the trainer. You should be able to do lots with the trainer: inverted, loops, tailslides, cuban 8s and a few other aerobatic manoeuvers. then move to a 'low wing plane, such as the every so popular Sig 4 Star series..
from there, you'll just be getting better, and better....