Metroplex, what are you going to use the 9mm for? Plinking or serious or both? Are you just interested in Colt or Colt style ARs?
I don't own a Colt 9MM, I have an OLY and use sten mags that cost me 3-7 bucks aeach with a socom block. I have yet to have a failure to feed or extract shooting Wolf, Win White box, 9mm Nato, Federal, Gold dots, umc and reloads. I have shot over 9000 rounds so far.