What type of headlights? I'm running Sylvania Silverstar 9003 S/T headlight bulbs(same fit as H-4 type) in my 2006 ZZR600 which is essentially the same as a 2000-2002 ZX6R "J". The bulbs are very bright. My headlights are properly aimed and I still get cagers turning there brights on when I'm running my low beams.
My next question for you is, why didn't you post this in the ZX6R or ZZR600 sub forums of the Kawasaki section?? You might have gotten a quicker answer to your question from other 2000-2002 ZX6R "J" model and 2005-2008 ZZR600 "J" model owners.
Check out post #1 of this thread, "Show off your ZZR600" almost every aftermarket part I have installed on my 2006 ZZR600 was purchased to fit a 2000-2002 ZX6R "J" model. If you have any other questions please feel free to ask. And please take a look at all the great info on mods etc. in the ZZR600 sub forum and the "ZZR Mods" forum. Lots of great stuff.
http://www.sportbikes.net/forums/zzr-600/310456-show-off-your-zzr600.html