General consensus is to buy a 02' if you are in the used market. Of course with US S2 prices being so low, why not get a 04' or 05' if you don't mind the lower redline. Some people complain about the tranny but mine is a MY00 and it's fine. Just take care of the synchros. Shift 1-2-3-4-5-6, not 1-3-6.

Be careful with the car. It's a handful with no mods, especially when the weather is bad. The first mod I recommend for new drivers is to replace the rear tires with 245's.

It's good on the track without a supercharger or turbo. More about driver's skill. Doug Hayashi, an amateur racer, from nsxfiles.com raced his near stock s2 (straight pipe w/hoosiers) and was nearly lapping as fast as a supercharged s2000. With that said, he would probably do even better with a s/c'd s2.

I don't think you need a turbo for autocrossing as that is more about driver skill. On the circuit more power will definately get you into more trouble if you do not have the experience.

Good luck.