There is a lot of debate out there about which choke tube is best for duck hunting, but ultimately it comes down to personal preference. Some hunters prefer a full choke for long-range shots, while others opt for a more open choke to allow for more shot pattern flexibility. You can also get purpose-built duck hunting chokes that have wider constrictions and shorter lengths to reduce the potential of flyers.
The best way to figure out which choke tube works best for you is to experiment with different types and see what gives you the best results. pattern your shotgun with different types of ammo and see how they perform at various ranges. Ultimately, you want a choke that provides consistent patterns and performs well at the range you plan on hunting.
Check this Ammofire selection of Choke Tubes For Duck Hunting.