hey Steve. the SSC class is the best class to start in, slower pace, cheap engines etc. the SSC planes are about 65 mph ad the open B gets up to close to 100 mph.

the rules for SSC states
.15 or smaller engine with a retail max of $85.00
400 sq in min on the wing area
2 1/2 lb minimum weight
17500 rpm max with a 8-3 prop

with a plane close to the min weight, they can be pretty fast, getting over 3 lbs and they start getting alot slower
the pilots also have to use some energy management, ie not to may loops or climbs. wind will also have an effect on the planes

if you look at the battle axe or avenger type planes, you will see the very long w.s. tall rudder and not muh else, that has become the standard combat design
The group here in CA likes to use semiscale coro warbirds and have had really good luck with them also, but then again, the long wing comes into play
Gnats are fun but they really are not that great of a comat plane, unless everybody has a gnat, then its fair game

its best to start ou and use what is used in that area. that way you can got to other areas and fly the normal stuff. check on the RCCA site for guys that in your area and talk to them, go see an event and have a great time!