Now this is the kinda game I like to play.
As mentioned by Blaxsun, ATT integration, full cap mags and good by to the restrictions as a first and foremost. Considering my current AR is one of the recent import Norc's and I don't really know too much about the fancier stuff. I would have to go with a DD or a Noveske or perhaps an HK. With a 14.5in barrel, free floated. I really like the look of the compact stock mentioned in post #5 or a MP UBR, Miad grip, and either the Elcan Specter DR (something about that thing makes me go from 6 to midnight), or a Night force of some description. Lots of Pmags. BCM mod 3, Throw in a BAD lever and it sounds ideal to me.
That is the beauty of the AR, its like lego, if you can think it up and have the funds, its possible.
Until then for me its a Norc CQA with a miad, random no name rail Eotech, and a sh!t load of the Russian MSF ammo.
T