A good tire to start off with would be like a Sand Tires Unlimited 21x12x8 Padla Brat 6 paddle rear, or a Skat Trak 21x10x8 6 or 7 paddle Hauler. If you want a V type paddle I would go with a Sand Tires Unlimited Sand Skate 1. 21x12x8. For more drag racing type application 22x11x8 6 paddle ULTRA Lite Hauler.
For the fronts I would get 21x8x10 Skat Trak Mohawks