Some progress to report on the 9600:
Managed to get it to boot Mac OS X 10.4.11 using XPostFacto4.
Had to do the install of 10.4 on an IDE drive (Maxtor 60GB) in a mobile rack carrier connected to the Quicksilver G4 800 Dual via FW. Went ahead and used Software Update to apply all the Apple OS and Security updates while still attached to the Quicksilver.
Then moved the mobile rack to the 9600 and inserted it in the receiver which was attached to IDE Channel 1 on an ACARD AEC-6260M PCI host adapter. Used XPF4 to apply the necessary components there and successfully boot into 10.4.11.
Parameters were 1. to make sure the install was done to the first partition on the drive, 2. the partition was less than 8GB in size, 3. the L2 Cache checkbox in XPF4 was unchecked (L2 Cache NOT enabled during boot) and 4. the speed during boot was set to 8 ... although I've since slowed it down even further to 10.
After doing that and getting it to boot successfully, I partitioned the OWC Mercury 3G SSD - which is connected to the ACARD AEC6260M IDE Channel 2 with a red Startech IDE to SATA adapter - to comply with the "less than 8GB partition rule" and used Carbon Copy Cloner to clone the boot partition off the Maxtor drive onto the first partition on the SSD.
That booted successfully as well ... so booting off IDE Channel 2 certainly seems like it works (I heard heard something to the contrary)
I then used CCC to clone the OS X boot partition on the SSD onto its 5th partition - which is almost 40GB into the SSD - to see if that would boot. It did ... so apparently using IDE host adapter resolves the "must be in the first 8GB rule" ...
Overall, it seems pretty stable so far ... obviously the performance is slower compared to the other machines here and the video redraw can be a little laggy at times ... but seems respectable given the capabilities of the machine.
Am having an issue with file copy performance across the network via the Gigabit NIC ... but I suspect that might be a driver related issue (or possibly a bad Cat 5e cable)
More to report later.