RE: Koas? Fourstar?
As everyone noted, the Kaos and Four Star are both excellent planes. You might also consider the Tiger 2, which flies mudh like the four star, and has a tricycle landing gear. I have had all three (still flying the Kaos) and have really liked all of them. You might want to consider the GP Easy Sport. It is an excellent plane, and although maybe a little bit closer to a trainer than the others, it can be quite aerobatic. My friend flew his Easy Sport for a long time, and then, believe it or not, advanced directly to a Spitfire, with no trouble. Fortunately, 40 sized sports planes are in abundance, and so many are good flyers (also worth mentioning are the super sportster, and the Goldberg Skylark. I am also flying the senior falcon, a wonderful airplane, but don't necessarily recommend it since it really requires a change in the dehidral, which is kind of a pain.