I have a pre-ban BM M4 profile under the handgurds 10 1/4" bbl. You don't see these very often with M-4 profile under the handguards. It has an A-1 FH on it now but I can swap it out for an A-2 Fh if you prefer. I also have a BM A-2 upper that I can throw in for $100. Both the barrel and the upper are compleat and in excellent condition with low round count. Probably about 200rds total. If you take both, I will include a charging handle as well.
I shot this on my pistol reciever and has some problems with cycling so I can't promise that it will work in your set up. I'm sure it is only a matter of tweaking something but I don't know enough about it so I tell you what is wrong. It might work fine in your gun because it may have been my bolt carrier or recoil assembly on my pistol that was causing the trouble. The pistols are problematic so I can't pin point anything.
This was cut down from a 16" M-4 and threaded by a gunsmiith. The threads are normal 1/2"x28 like all AR-15s so any muzzle device will work.
Sorry I don't have any pics. Feel free to ask any questions and I will do my best to answer them. Email is best as I don't check the PMs very often. I have lots of feedback and references all over the net and can provide as many as needed. Would also trade for a 7 1/2" bbl if you have one.