Of the two, Stag. Look at Rainier Arms, they are local for me but compete with Bravo Company. They take pride in not selling junk and Stag is, I think, their cheapest.
LMT is better though if you can swing it. I got an M4 upper, 14.5", and it is better than the Colt I was issued in the army. A lot better, but it looks pretty much the same. LMT will let cosmetic flaws through QC so if that bothers you you should inspect the actual weapon you intend to buy. I was told LMT did this to keep costs down. Noveske will scrap or sell as factory seconds parts with light roll marks, etc., but that obviously increases costs. Noveske does make fine stuff though. Try to get 1/7 twist whatever you get unless you plan on using it for varmint hunting a lot. Bushmaster likes 1/9 and 1/8, which is useless on a fighting rifle, and 1/8 is real common. But the 1/7 does better with the 62gr. and up bullets, and stabilizes 55gr. just fine. Your barrel first and trigger second, that is how you select an AR. Everything else can be junk or near junk and it will still be a good rifle if you get a good trigger and barrel. Trust me here, I built my Grendel using fairly cheap parts, not junk but not great, however, I got my hands on a Satern barrel and that made all the difference in the world, and a tuned RRA two stage topped it off. Sub-MOA and just wicked to the core.
What I'd do is get the LMT M4 upper (or whatever floats your boat) and the lower of your choice with the trigger of your choice. I had Rainier blind pin an AAC Brakeout, they did a great job --the guy that does the work is a Boeing welder and he does great work. If you go through Rainier, they'll even assemble it for you if you like or don't have the assembly gear. This is really nice for someone that wants to build their own rifle but doesn't want to invest the money in all that gear. Anyway, you'd come out for a little bit more than $800, but not much. The upper is $400something and the lower is too (assembled, ready to go LMT lower with stock and 2 stage trigger).
I went with a Noveske lower on my last build and will likely use them from now on. I used to think that lowers were lowers, but after getting a cheaper but decent Aero Precision and a Noveske side by side, I can say the Noveske has much closer tolerances. The fit has no equal. If you build the rifle, the extra $50 for the Noveske lower is definitely worth it in my opinion.
Lots of good options today, this is the era of the AR. It truly has become the All American rifle, like it or not, and we have a plethora of parts to choose from. Just keep away from the junk and you'll be okay.
As far as DPMS, they are okay. Not great, not bad, just okay. I had a LRR in .308, one of the first ones, and it wasn't anything to write about. I sold it. But others swear by them, and I have used their parts --my favorite rifle, the 6.5G, it uses a DPMS upper and lower small parts kit. But now I use JP Ent., they make the BEST lower parts kit and they come without the hammer and trigger (and the absolute best bolt carrier on the market, bar none, their "Tactical" bolt carrier, I'll never use another one but).
I can say for a fact to stay away from Olympic Arms. They are just right down the street from me and I don't ever go there. They make junk, they know it, and they don't care. I couldn't even get them to make some small changes on parts for an entire infantry brigade to upgrade our M4's and make SDM rifles (they were close, so why not, and they did get the contract to test the SOPMOD gear, although I'll never know how). Their barrels were junk, their gas blocks blew off after 2000 rounds, and their FF rails system just can't stand any real abuse. These rifles are popular with newbies and Oly even has its own forum and the most popular thread is "why do people hate Oly so much?" and "how do I get my rifle to function reliably?". Enough said about them.
Colt ain't bad and I hear a lot of good stuff about Palmetto. If you want 3gun, go look at JP Ent. They cater to the 3g crowd. Now they will be out of your price range, but you can build similar rifles for less.
I have a LOT of AR building experience and I was one of the original SDM instructors in the army and we used M4's to 600m. I learned a lot about working on 'em, tweaking them, etc. Kind of became my thing. If you have specific questions, PM me. But go check out Rainier Arms, they have a good selection at good prices. Just make sure to check their prices against others, they aren't always the cheapest.
) and will chamber anything. 
