No matter what you do, paint, powder coat, grease, etc.... they will eventually start to show rust if you drive the truck and get them wet. To keep this to a minimum, you can have a spring shop punch holes in the ends of each leaf for a teflon wear pad, or you can add teflon strips that cover the whole leaf. These will eventually wear out if driven enough and cause the same rust problems.
Do not sandblast or bead blast with out taking them apart or you will never get all the rust and grit out.
Joe
