If you are buying a 20 gauge, the chokes are Huglu specific. I bought mine from Trulock, but Sumtoy builds them I believe and Carlson's sells them. I am running a Light Mod in one barrel and a Turkey .581 in the other barrel from my side by side. Getting good 30 yard killing patterns with Winchester Supreme 5's out of the 581 and a nice 5 - 15 yard pattern with Fiocchi Golden Pheasant 7.5's out of the LM barrel.
Daman