I think mountain biking pads work the best, they are super protective and made for moving around alot. They seem to stay on better than most others for me. Check out fox and 661 and if you can find them dainese (they are expensive but are by far the best). Most of these pads dont soak up much water either. Check out www.rhythmcycles.com
they usually have a pretty good selection and they are a colorado company so its cool to support them.