Seems a bit expensive if you are talking about going with the 80% lower, let the pros do it for the extra $100, if they screw it up they toss it and make a new one on the other hand you have to buy a new one if you make a mistake. It is a neat gun if you are sure that is the caliber you want, because you are going to be stuck with it. If I wanted on and was on the fence I would go with the Olympic Arms conversion kit. Appears to be around 720 new and uses a standard lower, in the end you are still going to need an upper with the AR-45 lower so the cost savings could be substantial. That being said there is some pretty neat stuff on the CNCgunsmithing website. Good luck and post pictures and reviews if you pull the trigger, pun intended, on that purchase.
I would definitely go with the 100% finished lower. On sale right now for $275...not bad for a custom billet lower that uses unmodified grease gun magazines. Slide fire stock and can! Most .45 is subsonic anyway. The armadillos wouldn't stand a chance. :thumb:
If I bought a complete upper, I think I am going to go with this guys builds. http://eisman.webhost4life.com/store/page3.html