Welcome to the forum !
I agree wholeheartedly with hihneast and his opinion on proprietary parts.
It may not matter to the guy who has a dozen AR's where half will accept alll mil spec parts, and they want some rifles with proprietary parts that float their boat.
But if you are goint to have 1 AR (good luck with that) it's a very good idea to stay away from proprietary parts.
We can't predict what the gun grabbers will do to restrict gun ownership, plus it is just easier and can be cheaper to have a fully mil spec or milspec+ rifle.
If you decide to stick with one and really enjoy shooting it, you may want to pick up a spare Bolt carrier Group (BCG) on sale, and many vendors offer a "oops-spare parts kit" if something if a spring gets launched during disassembly, or something breaks. There is aa saying, "One is none and 2 is one", which is why I suggest the spare BCG and a parts kit for those with one rifle. (this was me for a long time) You can find good BCG's on sale at PSA for around 50 bucks if you get on their email list and order quickly.
I also like the Springfield Armory AR's, but you will pay more than the Smith or the PSA. Like the Smith, the SA come with a life time warranty, and come with some features you may want. Rock River Arms is also putting out some entry level models that seem GTG,
although I have yet to shoot one. I have an RRA that has been flawless, and they have been around a while.
Recoil GunWorks runs LMT (Lewis Machine and Tool ) basic rifles on sale for between $849.00 and $899.00 every so often, and if that is in your budget, you can't go wrong. I remember trying to buy my first AR many years ago when the only thing my shop offered was Colt, and they were very proud of them. We have many quality AR's to choose from today. If your life may depend on it, I'd say stay away from the back of the magazine advertisements where guns may be dirt cheap, but may have inferior parts or assembly. Have fun !