I was originally going to go the CQ10 route but a couple of threads here gave me pause. I went the New Frontier Armory route for my build, and I am glad I did. I bought their upper and lower from runnerrunnerguns.com. I then did a little research here on this forum and amassed the rest of the parts. I built it up myself from scratch and it runs absolutely perfectly. Suppressed, unsuppressed any bullet weight, any brand of ammo. The fit and finish on my upper and lower are absolutely outstanding. They really look great.