Improve Torque

what is the best way to improve the torque on the s2000?? (no nitrous).. sooo which supercharger and more importantly which other mods besides a supercharger..

This is the only kit that I have seen in action and can recommend
http://www.vortechsuperchargers.com/product.php?p=120&cat_key=15

turbo>supercharger

turbo>supercharger

thanks.. i have done some more reasearch too and turbo i think is def the way to go..which ones are the best though

How about a 2.5 or 2.7 liter stroker? The car will drive like stock, except that it will have a lot of torque.