Odessa and grouseman have it right - use an open choke. Steel patterns tighter and a PATTERN is your friend. I shoot kent too, and prefer #3. If you hit them they die. I shoot both 2-3/4 inch and 3" shells. Not enough data to say which is best.
Another issue is whether you expect to have a shot at geese. IF so, you need to have some larger shot - at least BB - for early season grouse. Later in the season, when the polar geese come down, you will need BBB or T to drop them - they can have more than 1" of down and BB doesn't get their attention.
Most of all, just plan to enjoy the experience. If you were found in a swamp in the mud without a gun and duck license, you would be committed. . what does that say about us duk hunters? We are special and know a great time when we an have it!
