I was looking at tirerack.com for some 17" wheels for the summer, and noticed that the tire size recommendations differ depending on whether it's an 02 (presumable 00-03) and 04 (presumably 04-05).

For example, looking at SSR Competitions (17x8 (F) and 17x9

 

you would be absolutely fine using the '04 sizing, as long as the wheel offsets are in the "acceptable" range for the S2000

 

For the 03 and below it is considered a "plus" size from OEM so the computer keeps you at stock width. You can always change your rubber width to make your specific needs.

For the 04 and above it is OEM size so no change in width.

 

They are correct. The computer is just keeping you in OE sizes. Most people go with the 2004+ tire sizes or 225/45R17 front and 255/40R17 rear. All of these size will work on the car. It is just what you are looking for out of the tires and the car. A lot of time the tire size may be determined by the offset of the wheel.
If I can help let me know.