The URX has a proprietary barrel nut, which requires a special barrel nut wrench for installation. That barrel nut wrench is only made by... KAC. It will cost you more than $250 for the barrel nut wrench. Example: http://www.operationparts.com/KAC_Knight_s_Armament_URX_Barrel_Nut_Wrench_p/20495.htm Since you specified "or something similar," I'd start looking at what looks similar in your eyes - it's all up to you. Another option, if you're set on the URX, is to buy it from a vendor that will install it for free, for you. You'd have to ship them the upper, but they install your rail. One company that I can think of that does that is The Gun Gallery, in Florida. I like that look, too, but I went a different route - Troy MRF-308, with the KAC panels on it. Had bags of those panels stored away, anyway. Here's how mine ended up looking: Thread: http://308ar.com/forum/dpms-lr-308-general-technical-discussion/lr308-self-build/