Checked the DevNotes. Your 9600 uses the same MESH fast SCSI controller as the 9500, a Fast/Narrow (50 pin/8bit) SCSI II bus. That's just one horrible choke collar/leash to put on your Cheetah. You should look into a PCI Ultra Card to see any significant throughput improvements, no need for an adapter, just the internal cable.

You've got a SATA card in there for heaven's sake, go Ultra! ;D