What would work for paintball protection besides costly paintball slider shorts?
A cup and 2 pair of sweat pants and top.
padding you can make padding with old clothing and tape!
An ordinary athletic cup will offer protection where you need it most. Do you do a lot of sliding and rolling? If you do, you might find someone to sew a stretchy pocket on the sides of a pair of form-fitting athletic shorts (cycling shorts style, only without the butt padding) into which you can insert protective foam. It would be a fairly easy sewing project.