my suggestion would be to build one. Get a kit from Del-ton and a stripped lower and you're good to go. That way you get exactly what you want for between $600 and $1000.
I have a Panther Arms DPMS (southpaw) .223, red dot scope, a 30rd mag, 20rd mag, cleaning kit+oil, case and an extra rail. It has about 50 rds put through it. I have an ad posted on a local car forum IndyStars :: Log in=
Go see brett at seigals uniforms in downtown Evansville Cheapest prices he even beats Whittakers he carries DPMS Bushys and RRA he a suoer nice guy has lots of accessories on hand and is an armorer himself so he can even work on it right there provided your not going too nuts with it
I have a 20" colt Hbar model mt6700 like the 16" I sold ya only rifle length, $850. I can meet you at pops in indy again. I also know where there is a rockriver m4 as well.