The SPAD Flatbat is an excellent combat plane to begin with. There is also the SPAD HOR which is very sturdy for Combat, look at www.spadtothebone.com for the plans and get building!

A Magnum .15XL or OS 15LA with an 8x4 prop is a great combination for club combat. When you get into the larger engines like the .25 or .40, the speeds pickup and cause alot more damage when you midair.