Hi Jon,
Alloy etch primer followed by a good high solids satin black (Autogylm is brilliant) and then a satin clearcoat.....But with the cost of bleedin' rattle cans thesedays that would be the same cost as getting the Queen to paint it!
For the above reason the last couple I have done have been either powdercoated on anodized then it's doe and forget!
ATB, ED