Alot depends on what load your shooting 2.75", 3", 3.5"... Size of shot...whether it's Hevi-shot or Not...and how far away you want to shoot Ol' Tom....
If it were me and I were shooting 3"- #5 or 6's, and wanted the distance and density down field .... Kicks or Comp-N-choke with a constriction of .660 or .658....
same set-up using heavy-shot I'd go with a .660 Rhino tube or a .665 Hastings...
No Matter what you buy, you're goin' to the pattern board and try a bunch of shells to see what works best for you anyhow.... Just My $.02.... MTNMAN :wink: