What makes a good combat plane? Aside from the basic manuverability, speed, etc.

How can I achieve these qualities?

The trend right now is more disposable than durable to obtain a lighter weight wing loading and aprox 64" wing span. Some preffer a full symetrical airfoil as they can fly manuevers upside down as equally as rightside up. Some preffer semi symetrical as they dont really care for manuevering inverted all that much. The semi has lower stall speeds than the full....

Speed is not a factor as you can give up your streamer easily if you cannot handle the speed, something I do quite often.

Here are the best websites to learn all the tips and tricks.

www.rccombat.com
www.georgiacombat.com
www.texascombat.com