I agree on BCM, you really can't beat it for your application. I would look at a lightweight midlength barrel.
The biggest issue with assembling an AR isn't so much getting the parts together right - it's getting the right parts together.
US Army 1966-69, VFW Life Member, Retired Geek
Is this for duty? Are there any specific rule and regs you need to adhere to?
__________________ Assumption is the mother of all ****ups. Know what you know, Know what you don't know. -Paul Pedzolt "Jack of all trades, master of none, though oftentimes better than master of one" -Mynshul