these guys sell springs
http://cgi.ebay.co.uk/EBC-Clutch-Spring ... 45f205af4b
i know it's probably not what your after but you could ping them an email and see what they've got,
or try fowlers (expensive)
or try EBC who do clutch kits for fzr's although you might have to order one
hope that's some kind of help

have been told the RRs have a weakspot (the SP had another plate in there) in their clutch design, so may have to try some stiffer springs. after about 10 racing starts it started to feel like it was on its way out again....
may try new oem plates and steels, and some race springs for next season....

you could have a look at barnett clutches, they did have a few up on ebay, supposed to be race clutches.

the SP has the extra plate to deal with the high first gear, the RR having more standard ratios was I guess seen as being ok for road use.
It could be that in burning the clutch the steel plates have lost their roughness.