Both the spinner and prop are painted with Rustoleum rattle cans - no primer. Cleaned the prop blades with some acetone, and lightly sanded with 1200 grit (I think) emery. I figured if I didn't like it after it was done, it was a cheap and cheerful experiment. The spinner is still holding up well after 4 years. However, every spring during primping season, I dig the same rattle can out of the tool box, clean and sand JUST the leading edge of the prop and spray a couple of coats on the shiny side of the leading edge. Takes me a whole 30 minutes or so, including blanketing the plane. I've run through some minor rain, and overall, the rattle can stuff holds up better than expected. I figger the prop and spinner take slightly more abuse than a landing gear assembly.
The rest of the plane is Sherwin Williams Genesis 2 component urethane, though I had them mix up some enamel rattle can matching touch up paint.
Having said all that, if I were building and had my paint scheme picked out, I would powder coat the gear, and have a matching rattle can on hand for those wrench scrapes that no one but you will ever notice...