OP, regarding quality manufacturers, there are a lot of factors for what "good" is, but generally speaking you want maximum reliability first. After that, knowing your intended use will guide you more towards either durability or accuracy as your second highest priority.
Reliability generally comes down to how militant a manufacturer is in making sure their specs are followed, with QC gauging out well over a dozen specific items. Especially with ARs, this includes making sure the gas system is aligned properly, and sealed up properly, at places like the gas block and the gas key. There are a whole bunch of other factors that go into manufacturing a reliable AR, but all of these are key.
The lowest price AR I'd personally go with that meets these standards is Bravo Company Machine. Sons of Liberty Gun Works are religious in gauging and QC as well. FN's FN15 is a solid choice in the $1500ish range. Daniel Defense is a step up, and they arguably have some of the most durable barrels as well. You'd be well served by anything from those companies. LMT does have some baseline models below your budget, but most of their stuff is above $2500, and it's largely worth it. Blackout Defense is on the newer side, but they're making absolutely outstanding ARs. The top of the line for reliability and durability is probably Knights Armament. The latter two companies likely exceed your budget, but they're excellent.
One of the problems you run into with SBRs in 223/5.56 is that the pressure in the bore is spiking far closer to the gas port than either ARs or the ammo they run were designed for. This causes broken bolt lugs and extractors at relatively low round counts, made even worse by adding a suppressor. Most of these problems go away if you go with an SBR in .300 BLK, so that's an option you may consider putting some time into researching. You'll have to determine the balance of benefits for what you want to use your SBR for. BLK can allow you an even shorter barrel (7-9") and suppresses better, even with supersonic ammo, but may not be better at rural property distances, for example, than a 10.5" 5.56 would be.
One final thing I'll offer, is to not buy into the "just as good" mentality you'll hear from those choosing cheaper guns - your budget indicates you won't, but I want to make that point clear. It's not like every additional dollar you spend gets you an additional percentage point of performance - there's a point of diminishing returns that seems to kick in right around $1500-1800, where each extra dollar does get you more performance somewhere, but not as much as below that price point.
