The rules of what's legal to fly are fairly simple... 2 meters max length. 2 meters max wingspan 11 lbs max weight. You could fly a 72 inch square "Pizza Box Flyer" (the engine would stick out about right to hit the 2 meter max length) if you thought it might do the maneuvers. (It might actually be able to do the Sportsman series... but not competitively.)

A Four-Star 60 makes a NICE intro level Pattern plane. [img]i/expressions/face-icon-small-wink.gif[/img]