get an ar47 lower and an adams piston upper, best of bolth world.
the perfect ak47 mags with the ar15 accuracy, and the Cleanliness of a piston system.
this is the pricy way to do it.
or best of all bets, get the Sig 556r in 7.62x39 it also takes ak mags and is piston driven. i seen one at acadamy for $800
here is a good read also