I think that there were virtually no changes (graphics) from 99 to 00 to 01, but I could be wrong. If that's the case, then it should be a simple switch. Consult a parts manual or call your dealer and see if they are the same or not.
The big difference between the 99 and the 2000/20001 is the twin headlight system as opposed to the single light in the 1999. Kawasaki implimented the "cat-eye" look in 2000 and carried it on through 2001. It has the slightly pointed headlights for the front end. So my guess is if you ripped out the front fairing on both sides you may be able to swap it out for a 2000 headlight system. You might want to call Kawasaki in the parts department...they are usually pretty good about this stuff...be careful with the colors too, they are slightly different from year to year and the shades they use.
srzx6, I swapped out my 99 front fairing with a 2000. You will need to change the the headlights, instrument cluster (the bars will hit if not) and instrument cluster bracket. There will also be a little rewiring needed for wiring harness leading to the instrument cluster. It took me a little while to figure it out but after that, it was easy. Unless you get a real good deal on all of these things ($400 bucks in my case including the fairing) It going to cost you a grip. Here's my 99 with the 2000 front clip.