my advice, since you have a $1000 budget, is to get a cheapo like a S&W M&P sport, DPMS sportical or oracle, or Palmetto State Armory(heretoafter to be referred to as PSA), for the $600-ish range. shoot it a little and figure out what you want to change about it. a rock river arms match trigger can be had as low as $80 if you catch the right people during a sale, usually they are a little over $100 plus shipping. then fix the ergonomics, change the handguards, pistol grip, and buttstock should you so choose. then lastly decide what optics you want on it. my first AR15 was once known as a DPMS sportical but at this point it is no longer recognizable as such. it has a RRA trigger, badger ordnance free float handguard(free float ad some inherent accuracy but are a pain if you've never done them before and depending on the model you get), has a hogue pistol grip(for comfort) and it is topped off with a Nikon Prostaff scope... all could be done within your budget...
... heck of a lot better than spending $1000 for a cookie cutter Colt with no optics and no personally tailored features. oh, and mine shoots less than 1 inch groups with the right ammo, better than the guy behind the trigger.