Contact Frost Waterfowl in Georgetown SC, they advertise in Wildfowl, Delta Waterfowl, and others. They provide older birds that you can release.
As to hunting over live birds, it is only illegal if they are used as decoys.
Plenty of clubs release birds and hunt over them with no problem from Feds.
Taking a few ducks with you in the boat and tying them out as decoys is illegal, having them swimming around the impoundment does not seem to be. Just saying.
Pro staff: Pop Tarts, Little Debbie, Armour Vienna Sausage! Just an old duck hunter that grew up hunting from Moes lake to McGirts Lake in beautiful Sparkleberry Swamp.