Oil based "house" paint will work- Moore's
oil Impervo gloss ( they brand alkyd and latex paints the same these days). To get it to stick, the recommended primer is the semigloss oil finish paint (can't remember the name- also Moore). Put your nonskid on the prime coat and the Impervo will seal it nicely. You should get a few years out of it.
If you want to get fancy,
epoxy paint will last longer. (don't need the "marine" stuff)
Remember, prep is the key.