I would suggest Nuttall, willow, water, and cherrybark oak. I would advise against overcups if you are strictly planting as food for ducks. The first study below found deciduous holly was also a preferred food for ducks. According to a couple of studies, ducks actively selected for willow oak acorns because of their smaller size, thin shell, and high meat to shell ratio.
Foraging Habits of Mallards and Wood Ducks in a Bottomland Hardwood Forest in Texas
Acorn Selection by Female Wood Ducks
Mid-Winter Food Use and Body Weights of Mallards and Wood Ducks in Mississippi