I second the suggestion for the Tower Kaos. The Kaos is an old pattern design, but its a smooth, stable flyer that is an excellent platform for learning aerobatics. Its still a very popular design in the Senior Pattern Association for a reason. If you look at it closely, it looks like a standard trainer turned upside down with a symmetrical wing, which is probably how it started.

A new flyer in my club last year moved to a Kaos 40as his third plane. Its been a reliable favorite of his, and he's doing quite well.

Having said all that, if you're looking for a more scale appearance, the standard suite of Extras, Edges, and Yaks also can be very smooth aerobatic flyers. Just don't trim them completely neutral like the 3D flyers do and you'll be very happy. I don't recommend the Cap 232 as a plane to learn aerobatics on because of its tendency to snap very easily. This makes it great for performing aerobatics, but not learning.

Brad