I use “Createx AutoAir" latex paint for the color and then a two part automotive clear coat. (Dupont Croma clear) The auto clear coat is the only product, except epoxy paint, that will stand up to 30% nitro.
Both are way toxic, so wear the right gear or get your local body shop to do the clear. Often times if you talk nice they will do them for free (at the end of a car job)
http://www.autoaircolors.com/You can put automotive clear on most latex, enamel paints. You should test first.
Any more question?
Cheers