spoke with a guy who is ex-infantry and now doing semi-custom builds. I asked him about RRA (Mind you I have a 20" RRA complete rifle and love it) uppers and he said to be warry if you are mixing and matching. This is a good rule of thumb anyway you look at it. But, if you're going with RRA, just get a complete RRA.

Gman seems to be real happy with his Stag, and I'm pleased with my 8 year old Bushmaster. Just look for true milspec components. They will run a tad more, but not enough to pink too hard. LMT has a nice rig too.

Take a look at Free Floating the upper if accuracy is the desire. you might even investigate the 18" uppers (aka mid length) as a compromise between that arena.

As for sights, look at the A.R.M.S. #40L ... and if you're looking for a good mounting/ring setup for your optic (if your going for a real scope vs. red dot or holosight) don't skimp, get the Larue SPR mount. It's about $190, but damn well worth it.

Still for your first one I'd say buy off the shelf and get the same manufacturer for both components. Folks around here can hook you up with some parts that we don't need anymore and are willing to part with for a reasonable price.. just post in the wanted area.

Welcome to the addiction!