Well now, a useful update for those still considering the mod
Thanks to Debtman for pointing this out - Wemoto are now stocking YSS emulator valves for £68. Saves on all that International postage and Import Tax tomfoolery
http://www.wemoto.com/bikes/yamaha/fzs_600_fazer_sp/00/picture/fork_valves/
I should probably rename this thread to YSS Emulators...
Thanks for that link, it was on the first page of a Google search, you sure you're not a Google employee
Work for them !don't make me laugh I think Jeff owns Google.
If you are seriously thinking about the upgrade to emulators I can vouch for the quality of the ride after the work is done, provided its done methodically, its important to work accurately and cleanly leaving no bits of swarf anywhere with in the fork tubes, be exacting when it come to measuring out the holes in the damper rods to overcome the damping effect of the rods themselves.
Couple this with some quality weight matched linear springs and the ride will be transformed, the only issue will be the back end will feel like a bowl of jelly if you still on the original Yamaha yoo yoo damper. I went the Nitron R1 shocker route, but, their is a member (DevilsYam) on here that can supply you with a R6 shocker for a very reasonable price, and I have heard guys raving about them.
One other thing thing about the Emulators is that the later bikes had damper rods that are a little shorter than the earlier models and this effects the height that you start to drill out the damper rods.
I did my 2003 FZS 600 last winter and it has transformed the handling for me, the Mrs said that it is a better ride on the pillion as well as it has taken out the shock/jarring of suspension bottoming out but most of that will be down to the rear upgrade (the bikes not hers), but the front end is smoother has more feel, feels hunkered down on the surface and inspires confidence.
Good luck with the upgrade should you decide to do it.
lots of info on the site, Jeff (Kebab) has written loads on the upgrade.