RE: mod. choke
If I only had to shoot one choke for EVERYTHING, it would be a modified. It works with lead on doves (if you let them get out from you a bit), works great with hevi shot/hevi steel/steel proper in almost any waterfowling situation.
I do always carry an IC tube with me when I duck hunt, you never know... sometimes you end up finding a tight spot where the ducks just want to be. Doesn't take up space or weigh much. If there is a possibilty for a 30+ yard shot however, I'll take my modified everytime.
The faststeel isn't a bad choice. I have my own personal preferences, but for the price you are getting it (free) I sure would shoot it!