Just found this Arkan. This is a good freaking deal. Throw in the Rock River Arms bolt carrier, A3 flat top (instead of the Saber Defense one), maybe the Vortex Flash hider (which supposedly is freaking awesome but a regular A2 flash hider is good enough) and charging handle and you are set.
http://www.pkfirearms.com/store/get_...action=display
Or this with a 10 inch RAS instead of 13...personally i like the first link with the less exposed barrel.
http://www.pkfirearms.com/store/get_...action=display
This is the set up I am getting
http://www.pkfirearms.com/store/get_...action=display
Pkfirearms is good also.