Regarding the hydraulic clutch system, one option would be to buy just the slave cylinder (also available at american classix) for $275 and buy a used hydraulic clutch set up off of eBay. I just saw one for about $30 from a Kaw ZRX1100. The cylinder is still a lot of money though...
On the clutch springs, I have been told by quite a few experienced racers/builders that stock kaw springs are just fine unless you have a turbo or nitrous. I got rid of my heavy duty springs and I like it much better. Your clutch cable will last much longer too. I also installed a needle bearing clutch pusher which seems to help. Good luck!
The Kaw List:
Current: 79 KZ1000 A3 MKII, 78 KZ1000 A2, 78 KZ1000 Z1-R, 78 KZ650 SR, 80 KE175
Former: 03 KLX400SR, 99 ZRX1000, 82 KZ750 LTD, 80 KZ1000 A4 MKII, 80 KZ1000 LTD, 78 KZ1000 A2, 74 H-2 750 Triple, 78 KL250
