I was checking in my files for you..... 1/7/10 is the boot block date of the "revision 1" motherboard. So, you have the original motherboard rather than the updated one.
If you want to do the project it is not too bad to swap in one of the more recent motherboards.
SSD will get you the most bang for the buck in terms of speed boost. I think the Z600 is still a SATA Gen II motherboard (check on that... my recollection is that the use of SATA Gen III drives started with the Z620, and there may be issues if you try SATA Gen III drives in a SATA Gen II workstation according to HP). Assuming it is a SATA Gen II workstation then my favorite for that is the Intel 320 series 300GB version. You can find those new on eBay for a very reasonable cost. I have also bought them used off eBay and almost always the life left reported by the excellent Intel "Toolbox" software is 100%. That same software allows you to update the SSDs firmware very easily, if needed.
