I would go with a World Models Super Stunts 40. I have one and I love it. It's been my work horse for 9yrs now wit well over 500 flights. In April I just ripped off all the covering and went through the airframe. I probably should have retired due to age but I like it way too much. My Super Stunts is using a Tower Hobbies .46 engine swinging a 10x7 prop with a top speed at level flight of 86mph (according to my gps). It has a large wing and very low wing loading so it can be slowed down to a crawl, but the fully symmetrical airfoil allows for enough aerobatics to keep you interested.