Scott, my 1st choice would be accuracy speaks, Derek is a competitor and a top notch smith for the whole package, trigger, barrel, sights etc..., Fulton Armory is also top quality, White Oak armament is also great, as is compass lake. I am an M1a man myself in this competition, but have now built an AR, as to 600, with the right package, excels, I hate it, but the record book shows the truth. With the right combo. The cool thing about the AR is you can build it yourself, and I mean really accurate, but these guys won't do you wrong.
Best of luck, love US service rifle.