Im thinking of doing the build with a Larue stealth 18" upper with 13.2" hand guard. Either a Spike's or LMT lower (depending on who has the better military discount)and topping it off with a 1-10/2-10 FFP optic with 3/4 rails and Leupold aim point for clearing building's. Anyone build something similar to this or have any range report's from the Larue Stealth uppers?