Looks like a very cool project. How about you dispense with the idea of carpet altogether and get some alkyd paint in a color you like or more of the epoxy and add a couple handfuls of sand or purchase some sort of paint texture additive (same thing more or less) and paint the floor for a non-slick surface? If you regularly check Lowe's or HD, you can find mistinted paint cheaply. Sometimes you can even talk them into adding a bit more tint if it is an off color. I bought a gallon of alkyd paint once for a dollar.