I pretty much always use a modified steel choke on both my guns. As far as shot goes... for the wood duck, being a smaller bird I would go with 3" number 4 shot same as I would with teal. On Mallards I like to push up to a 3 1/2" #2 shot but will sometimes shoot 3" #2's. Again it's personal preferance. I know guys who shoot BB and others who shoot 4 shot at big duck.