RE: Beginner's First Aircraft Choice
If I was you I'd forget about those "boring" trainers with all that dihedral that lets the wind take them anywhere and get myself a goldberg tiger 60. Flys much better than a trainer, very aerobatic, and cuts through the wind so easily, along with, it will land on a dime! Aerobatics are so easy with it and will make you look like a seasoned flyer.
As far as the piper cub and aerobatics, that all depends who's behind the controls. That is, with a clipped wing and not that big "surf board" full wing as minnflyer once mentioned.
Good luck on your decision,
big dan