Well, I've decided that a 9mm AR would be very cool.  I was hoping the guys here could help me out with suggestions for configuration.  I am pretty good with building an AR both lowers and uppers.  I have all my own tools and have done quite a few.  Basically, please give me suggestions for what to get, I'm looking for the best value, not necessarily the cheapest.  

These are just my opinions, BUT - I have had no problems with either of my OLY 9mm uppers.  One has 5,000 rds thru it & the other is at 6,000 rds.  VERY accurate & reliable.  Both are flat tops, you can allways put a bugout handle on later if needed.  I use the SOCOM blocks and unmodified Sten mags.   I bought both uppers thru Atlantic & can only say GOOD things about them.   Only (problem) is how fast I go thru ammo! -WAY TOO MUCH FUN - Good Luck, ALLONS11

I have a Rock River upper I put on a Pre ban Lower I have. The rifle is flawless except for the mags that I just can't get.