I don't know what the breaching choke would be, cylinder I would think, looks cool, not much use unless you are playing Rambo, but would be fine with slugs,
Modified is good , for average distance, long range , full choke would be better.
Phone the store and see what was suppose to be with the gun, likely what you got, the only other I would like would be a skeet or IC, with is about the same.
That was what I used on pigeon's and magpies, those suckers are gun smart.
Put some grease on the choke threads, and take them out and clean and relube after use, I have seen choke tubes left for years in a gun and a pita to get out
Good advice here. I'll add that "never seize" the silver/grey stuff is the grease you should use on the threads. Further, these are really fine threads, ensure you don't cross thread anything by almost seating them by hand. Don't force anything, if it's tight, it ain't right.