You need to try various combinations of shell and choke, on patterning boards, before going in the woods. Not all shells and all chokes work the best in combination, and what works for my gun might not work the same in yours. Also, polish your barrel. I think there are some old posts on that to review. Adds to pattern effectiveness.

Vest--I'd say buy a SuperElite II if you can afford it, if not, wait a year, put it on your birthday/Christmas gift list, etc., and spend the money this year on shells and patterning your gun/choke combo.