[Overdriven]

I think you're right about the width, the inside edge of the tires will be pretty close to the body if your 18" measurement is to the outside edge of the tires. Integy has extended hexes in a variety of lengths up to 30mm I think. Idk what the xl ones are. You're brace idea for the motor area couldn't hurt, it is going to be a heavy truck after all. Could make another brace for the other side and put a spreader between them making it a grab handle too.

Btw, I've heard the Redcat bodies arent that durable, the lexan is kind of brittle instead of flexible and that reinforcement is a good idea in some areas.