Do you have access to a glass beader/blasting cabinet? If your going to do most of the work yourself it might be a good investment. If you blast most metal surfaces clean follow with a good marine or self etching primer,(found in a spray can) and good quality paint will work for most of your parts.
Just read your post again about the blast cabinet
I've had good luck with epoxy paint in the can as well as shooting stuff out of the gun.