Looking at Jebs and Sumtoy using foxtrot ammo 3in #9 or 8.5
There's a lot of good choke makers our there, I'm not shooting a Franchi but a Benelli and I've shot some excellent TSS patterns with Carlsons.
562 if you looking for a hot pattern. 570 more hunter friendly
I run a .570 Sumtoy with foxtrot #9 and it's a great pattern. It also patterned the rogue 9's very well.