You might check out this stuff. Do it yourself, but pretty good quality.
I have used it before. The last time was on the outside of a dump truck box. I actually got the "smooth" rather then the textured stuff. Paint would never last on the outside of the box, it would get knocked off, then start rusting right away. Its just now starting to bubble in a few places, but it has probably been at least 6yrs ago. I just rolled it on with paint roller. The "smooth" ended up having a pretty heavy orange texture to it.