Was going to buy a PWS upper 10.5 . But for 300 more I can get the whole rifle . Who else makes a bad ass upper . And who do you guys think makes the most bad all AR right now. I just finished building a sweet aero precision AR pics coming monolithic upper rifle are the new wave im told.
http://aeroprecisionusa.com/upper-receviers/cop-c4-ar15-continuous-optics-platform-carbine-kit.html

I prefer parts guns. Do you have a SBR lower already?  Otherwise I'd build a pistol and wait for the stamp. If you buy a 10.5 you'll be waiting awhile.

PWS now ships all their "pistol" AR's with a Sig Brace to install on the buffer tube.  Rock that guy while you're waiting for the Form One to process on your SBR.  Once the paperwork comes back swap out the buffer tube for a rifle buffer tube and enjoy your collapsible stock.