New upper build
Honestly, I don't think you can go wrong with Robb at Virginia Arms. In addition to being a wealth of knowledge, he most probably has all the parts you need in stock. Most on this board know him as GotM4. He put together my 10" upper and is in the process of building me up a 14.5" one. Very high quality work and I couldn't be happier. Call me bias if you will because he's my teammate, but GotM4 will build you a top quality upper.
Team Virginia Arms member
USPSA Limited B and Production C shooter, IDPA SSP-SS
formerly known as TacticalShooter