aim for something 1998 onwards, as they shed quite a few kilos then. they made lots of little changes right up until they stopped making them around 2003, but essentially much the same bike still.
have a read of these reviews:
http://www.mcnews.com.au/Testing/zx9r.htm
http://www.mcnews.com/mcnews/articles/maddogs.htm
the all new 1998 9R came out around the same time as the yamaha R1 so it kinda lost a lot of the lime light, as good a bike as it was... tho all the magazines referred to the 9R as the "blade beater"

in HP terms the 9R was right up there with the R1, but the blade was really lacking. the 9R had the highest top speed tho, good aero and ram air system. the blade was a tiny bit sharper on the track tho, but all the reviews said the 9R was by far the best bike on the road.
i recon mine works pretty well on the track tho

just need higher rearsets for that tiny bit more lean angle, but they are fine where they are on the street