hi I'm 17 almost 18 and been trying to figure this all out. i still have no idea what bike i want use. i know i want to have in mounted in-frame. i plan on putting a shift kit on it when sick bike parts gets it in stock so it has to be a mountain bike. and I'm gonna use the ZB-80 motor kit from pirate cycles. btw i plan on doing all this for around $600 so im looking for a bike thats about $150 or so. any suggestions?