All these guys have recommended great planes but i have another one. My second plane was a Seagull Spacewalker II it is a low wing scale tail dragger that is pretty forgiving. I maidened mine (but I had a few more gallons of fuel thru my Nextar ). It isn't as aerobatic as some of the other suggestions but will do alot more than your trainer and has very few bad habits. It flies (and lands) a little faster than a trainer but that is what you need now any way. No matter what you choose just have a blast with it and fly the wings off.

Just my 2 cents.