My match AR is close to 7lbs. Here's what I have on it: 18" Nordic 1:8 Rifle length gas barrel (made by Wilson), AP customs 15" Carbon fiber forend, Mag tactical lower, Magpul CTR, and a Burris XTR in a PEPR mount. If you want more of an SPR you can always throw a Bipod on it.
I think a carbon...