I think the spads and the [link=http://www.duraplane.com]Duraplane[/link] are good bets.

And to be honest, you really have to auger a trainer into the ground to destroy it. Years ago (when I was in the hobby for the first time) I saw a guy cartwheel a PT-40. He broke a spar and something in the fuse. He glued it with epoxy taped down some loose covering and flew a couple more times that day.

Just something to think about.