1) At $1000, your money will treat you best with a personal build. Folks lacking AR experience are often a bit intimidated by the prospects of building their own. They need not be. Doing it right requires only a bit of research (to sort out what specs you
desire and the best place to get them), and the skill required to assemble a model airplane. And posters on this board are generally happy to point you in the right direction. There are also an abundance of YouTube videos that will walk you through the process.
2) You want it complete, period? In my opinion, nobody aptly competes with PSA
quality for under $1000. They mostly sell build parts/kits, but also offer complete rifles. You can get a really good complete rifle there for $700-800 (that will measure up well to an $1100+ Colt), and $200-300 more can produce a really good mil-spec rifle with a $200-400 red dot sight. Whether you're building or buying complete, PSA offers the best bang for your buck in the industry in my opinion.
When you're talking general multi-purpose ARs, my preferences are PSA for anything $700-1100, BCM builds for $1100+, and Daniel Defense complete rifles for around $1400. Just my own personal preference, but that recipe is shared by many on this board.
I'd suggest you start watching PSA for an opportune setup. Their stuff is constantly going on sale for 25+% off. Once you figure out what exactly you want, you probably need only be patient for a matter days before it's offered at a killer price.