Maybe you can get together with a few of your friends to differ costs and see what patterns best of of your shotgun/choke combination. Pattern different loads and go with what gives your the best pattern.
Take into account your shooting abilities. Are you going with steel or another non tox shot. In steel I'd stick with 2's &3's if they pattern well a good choice for good pattern density and hitting power use the one that patterns best. In other non tox you could got to 4's or even 6's again take into account you abilities..
My personal preference is steel 3's with mod chokes in both barrels and I keep shots to nder 45 yards no matter what. They work on both ducks and geese if you respect your limitations. Hitting birds in the body is not my idea of good shooting hence my use of tight chokes.