From my experience, 25-30 yds is a good distance for an upland gun...I shoot a Benelli M-2, 20 gauge mostly...Steel 7's seem to be the ideal shot size for small soft feathered birds, like dove & quail...The only choke I ever use is the Benelli factory modified (turkeys excepted) for upland or waterfowl hunting.
I think this is one of the most over thought out processes there is...2 cents.