Brian, Latex is just fine for gassers and a clear coat is only needed to help in any clean up but there isn't much clean up required with a gasser. I do use exterior Latex though, it doesn't fade in the sun, that's the only reason I use the exterior. I just finished painting my 60 size float plane and ended up using all two part epoxy. The yellow base coat is Klass Kote and I didn't bother with a primer, it sticks well onto the glass. I used Deft Sanding Lacquer Sealer to glass the plane with. I ended up using about 1 pint of yellow to paint the complete plane, both side skirts for the floats and the land gear plus the floats. Klass Kote covers very well. I will post a photo of last summers build, an 80 inch Sukhoi and I used nothing but latex paint, just yellow and black. No primer under it either. Just finish sanded with 220 grit paper. The Sukhoi has no primer or over coat and holds up very well on a gasser.