I have a Tandem Motors 1100cc buggy with tire sizes of 25X10-12 & 25X8-12. I'm new to paddle tires, I don't seem to see these size available. What size paddle tire should I be looking for? Does wheel size matter or best wheel size for me? Any good places to suggest for a best price on a package deal on tire/wheels.
Thanks

I could get you the same setup that Joyner uses on their 1100.

Glade

I would buy the ITP Dune Star 26x10x12 paddles for the rear. They are lightweight, high quality tires. Sand tires should be run at a lower pressure than dirt tires, so even though they're an inch taller, that inch will probably be offset by the sag created by the lower pressure.
For the front, I would probably run the AMS Diamondtrack 27x9x12 ribbed tires. Same with the rear, lower pressure, so they won't really sit at 27". Again, they are very light weight so they allow the suspension to work better and you'll get better floatation to keep you on top of the sand. They are directional, meaning that you need to buy one left and one right because the ribs are cupped. The cupped edge faces out and allows the tire on the outside of the turn to dig in and grip better. My quad has the same kind of front tires and they really work well. You can go sideways across the face of a dune and the front end still tracks straight.
The rears are about $80 each and the fronts are about $75 each through Rockymountainatv.com. They also offer free shipping on orders over $150. They are a really great store with excellent customer service; I've been buying motorcycle and ATV parts from them for years.