A few magnum decoys will make plenty of motion in a regular sized set up. You can give it a try and see how the ducks react. If they start to flare off of it or don't seem to be working like they should then just swap them out with duck decoys. Every set up should have a jerk string in it. I prefer that over spinners any day.
Don't know, don't count the beers I drink anymore either. -Poor redneck