RE: choosing second plane
IF.... you can talk somebody into it..... Maybe they will let you fly their Extra or Edge for a few minutes. Possibly on a buddy box for safety???
Also try some of the sport planes out there. Many are VERY capable fliers. Will do any of the aerobatic maneuvers, maybe not quite as precisely as a an Edge or Extra, but still capable.
What does your instructor fly? Try out his stuff. If he won't let you, maybe he is not as confident in your abilities as he says he is?????
IMO Jumping from a trainer to an Edge or similar, is like going from drivers training to an Indy car. Not saying you cant driver the thing, but most likely it is above your skill level and an accident is much more likely to happen.
I sure there are many more opinions out there in both directions. Good luck on your quest!!
Ken