Still not having any luck whatsoever... starting to get extremely frustrated. I installed Proxmox 3.0 temporarily to see what would happen. Amazingly, PCI passthrough with the Adaptec 7805 worked perfectly fine... only problem was, performance was completely terrible.
I was only able to achieve 30-40MBytes/sec reading and writing to to the RAID10 array. On my current (non-virtualized) environment, I can saturate a GigE link @ 100-110MBytes/sec using an Adaptec 5805 and SAS 3.0Gb/s drives. This is a gigantic bummer because I REALLY do not want to use Proxmox, it is nowhere near as polished and robust as ESXi and seems very kludge-y to me.
Any suggestions? Are there any official lines of support I can contact who may be able to help, since this is all supported hardware? I had planned on paying for ESXi, but not if it doesn't work. Therein lies the problem...