Jeez, get a complete mechbox. Cheaper and already fit together. Drop it in and you are good to go...
http://www.redwolfairsoft.com/redwol...l?prodID=21323
BUT, I completely agree with the PTW plugging. Having spent the equivalent getting an armalite up to handling 500fps, it was a complete waste of time and money. The PTW I picked up was 10x the gun, in both trigger response and reliability. In the end, don't regret it, save up and get the best from the start. Your pocket book will thank you (ha ha ha, maybe)...
-Daes