Well I blew the dust off the machine, I have the H200 already and 4 1TB drives. My unit only has the single power supply. I'm not seeing very much in the way of extra power connections to add drives.... hmm I will need to re-read your posts. Even with the slower SATA II connections on the MB I was hoping I could just try out a "JBOD" setup to see how it worked.
I have the Xeon 3430 and 4GB of RAM which both seem light if running VM's and such. I'll see if I can fight through a few firmware updates, etc. and spin this up. I have a low power Plex server already (HP 290) so I guess I don't need to mess with the video cards, more of a curiosity.
I'll probably look at power with my setup too while I'm going through this and share some numbers for others to see - newer hardware would probably pay for itself pretty quick where I am @ $0.20/kWh