I would go with a eton 40, they have a remote killswitch and it will be perfect for his size. Also eton motors are bulletproof and there is a shit load of aftermarket for them. My son started out on a viper 50, which is now a bigbore ported 70cc it holds its own with stock blasters. Cant go wrong with the money, Im not knocking the brand above but wait until something breaks on it, trying to find parts is going to be a bitch.