I suggest Duracoat. They have a new aerosol shake and spray kit, which you don't need an airbrush to apply.
http://duracoat-firearm-finishes.com/
Simple proceedure, just follow the instructions and your good to go.
I've used Duracoat on a few guns with great results, and even used it on custom motorcycle projects, knives, and Jeep parts. I've very durable stuff and stands up to any cleaning products I've used.