Another that would recommend talking with Mike at D-Tech..I've got 3 of his uppers including a 23" + D-tech comp. fully fluted in .204 Shilen barrel, a 20" fully fluted .223 Shilen, and a 22" + D-tech comp. fully fluted Shilen .243 wssm. As has been stated, Mike knows AR's and builds'em as good or better than most. Very knowledgeable and easy to talk to.

Most important thing on the lower is the trigger. A guy could put a piece of tape over the maker of most lowers and most of us wouldn't be able to tell who the maker was of each.