As others have said, regular wax is fine, I've used plain old meguiars carnuba wax on both painted and powdercoated wheels, I keep a dedicated tin of wax and applicator for wheels, if wheels have been in use for a while first you can clay bar them too, I've used old clay bar that I no longer use on the vehicle's paint for wheels and it works great. 2 years ago I had some wheels refinished and now I get in the habit of waxing them as soon as I take them off for the season before I put them away, I'm using Akebono Ceramic pads with my Tundra Brake upgrade and I don't ever see a hint of brake dust on my wheels...