You could always look around for one of the old Browning A-5's the army air force used to train bomber gunners to lead aircraft with during WW2. I saw a pair of them in a shop in Albuerquerque back in my college days. Don't have the whole tacticool thing going, but an interesting footnote.
Yeah saw the AA-12 a while back. I think the AA-12 is better than the Saigas just because the AA-12 seems to have less recoil. Better recovery for the next shot or burst of shots....