Might not handle wide enough pieces for you but until you find what you are looking for, I've seen several jigs for thickness sanding using a sanding drum on the drill press. If you have a oscillating sander you can setup up a similar jig for that. This one is from Shop Notes Magazine.
Here is video of a simple one,
--Nathan, TX. Hire the lazy man. He may not do as much work but that's because he will find a better way.