just my .02...

Get an auto body shop to do the whole thing for you. They can media blast it, and paint it with durable automotive paint and bake it in just like a proper Auto paint job. If you spray bomb it you might get good results if you are really immaculate with your prep work and very patient but unless you cure it for a long time it will never be nearly as durable as an automotive paint job.

I went through all this with my Raleigh Super Course in the not-so-distant past and the cost of materials to do it properly myself would have been easily as much as the $150 the auto body shop charged me....i saved some cash AND got a better paint job than I could have done myself.