Something you may want to consider is Stans Sealant. It is what many of the Wisconsin pro/semi-pro/Elite racers use as well as some of the Sports and Citizens.

I'll be converting my tires over next year. Then I can ditch all the tubes and CO2. I race XC and the less I carry, the better.

Here are some reviews of this product...
http://www.mtbr.com/reviews/tubeless...t_122417.shtml