[Theory6RobotiX]

You could very well use the kit gearboxes with the small CIMs. Four wheel drive is a good idea if you are planning to go up the ramp, and u need 4'' off the floor clearance to climb the ramp. If you are using the wheels from the kit, it is a good idea to cover it with tread(at least two) because if u get into pushing contests(likely to happen), the wheels will have no traction and your robot will be pushed around.