Okay, I did my research and pulled the trigger on my roof coating. I ordered a 2-part urethane product called Raptor.
As with any paint coating job the devil is in the prep work. I pulled the roof rack off first and started sanding. No way I was going to sand thru all that rust, so I got it fairly smooth, treated it with phosphoric, scrubbed with soda and water, dried it, then coated with rust stop metal primer.
I should mention here this will be a 2-stage process. I'm masking off the outside edge of the main water channels and applying the bedliner between and under the roof rack rails. I'll touch up the blue as needed outside the rails, plus deal with the hood separately.
The Raptor coating comes as a kit, spray or roller. I don't want to deal with spraying, and the roller kit is a little more than needed for the roof, (and half the price)so that was perfect. It comes with texture rollers, but I'm using smooth foam. It also comes with silica grip media to be mixed in before application which I am leaving out.
I'll post pics soon.