Brownells is having a 10 % off/free shipping sale through today.
A Colt AR6720 lightweight carbine is $847 shipped with the discount. That comes with the fixed front sight, backup iron sight, pencil barrel, basic furniture, and at least one Magpul 30 rd magazine for $150 under your budget.
The 6720s are supposedly under 6.5 lbs., so certainly light weight.
https://www.brownells.com/firearms/r...39-183849.aspx