I am building another 7.62X39 AR and the barrel I got has the 1/2X36 thread cut for the FH. As far as I can tell the only FH in this thread cut was made for the 9MM barrels. The A2 style, which in its self isn't so bad other than being large in diameter.
So I contacted CNC Warrior about my dilemma. They happened to have some FH fresh off the presses without thread cut in them yet. He said he would and he did!
So here is the first (as far as I know) the first option you have:
CNC Warrior :: 1/2-36 PKM Short Flash Hider $23.99
Here is the next one he said he was working on that will be on his site soon:
CNC Warrior :: Saiga Flame $37.99