All you would need is a stripped lower receiver and a go getter attitude and you could end up with a decent 6-700 dollar rifle. There's even a how-to stickied in this very forum on assembling the lower receiver. Just another option to consider. Built my first one with very little knowledge of the platform with the help of some of the good fellas on this site
They are pretty much the new kid on the block and seem to be of respectable quality. People seem to really like em. Get em while they are cheap I'd recommend going with a mid length, you won't regret it
"If guns kill people then does that mean the spoon is the reason Rosie O'Donnell is fat"
If i were you i'd try to get the Rock River Arms Tactical Operator 2 for $1k. I know your budget is $1k or below but trust me owning an AR is addictive and sky is the limit. So might as well get one of the best brands as possible. My first AR is DD and it was way more than my budget. Now i'm addicted and planning to get another one like RRA or Spike's.
But this is just my opinion.. don't take my word for it.