Go with a 2-component clear urethane, and it'll never chip off. I sell paint in the Seattle area, but I'm sure if you go to any reputable industrial paint store, they should be able to set you up. If you were near me, I'd put this in your hands:

http://www.roddapaint.com/industrial/product-search/product-detail/299/armourshield-urethane

We only make it in a gloss, but it can be flattened with OK412 powder. Since it's a 2-component product, you'd have to use a paint gun, but it would stand up to just about anything you throw at it (as would most any 2k urethane product).