I keep it simple. I tried the collapsible, and pistol griped stock, and went back to a field stock. As for the ACE stock, I have one on my AR15 it's a great stock, but the only thing I don't like about it is that it's pad is a bit too narrow; although the pad is quick soft I still don't recommend using it to blunt the recoil of a shotgun due to its small diameter. The buffer tube on the stock is quite thick, and is designed to keep the receiver extension tube from bending which will seize up your AR if that does happen, but the thick tube isn't necessary on a shotgun. As for a stock adapter I'd probably only use a Mesa myself.