If turkey, duck & pheasant are the main prey I'd go
with the 12ga. Myself, I like an auto-loader for this
type hunting. As for specific makes/models, the best
thing to do is handle as many as possible. Go to a shop
or gun show with alot of options. Fit and feel mean alot.
Costs can go from a couple hundred to a thousand or more
so there's alot to choose from. And if your like most this
will not be your last shotgun purchase so there's really no
wrong answer.
Good luck, I hope you get what you want.

PK