Buy a Werks B2 or a Novarossi 3 port. You have never driven a .21 powered buggy before. You won't have any use for a modded motor or for that matter for a good top of the line motor. Budget motors are the best way to learn about engine tuning and to learn about driving. There is a steep learning curve with tuning motors and with driving. If you screw it up you are going to kill your engine. You are going to screw up. That is just part of the hobby. Screw up with a cheap motor so you can afford to just buy a new one instead of trying to keep a motor running because you spent a lot of money on it.