Thanks so much for taking the time to reply and suggest something.
I did try both RAID and Un-RAID setups and the same problem persists... none of the drives are visible once I get into the Disk Utility screen after Clover Boot. They are however all visible to Clover prior to me selecting 'External' and proceeding with the installation instructions per this guide.
Seems pretty clear that something is missing (device drivers) that permit the OS X install to actually see the drives (any of them) in RAID or not. I have built 100's of machines over the years, but this is my first Hackintosh attempt so I am positive I am doing something stupid, but can't for the life of me figure it out.
Thanks again for taking the time to reply and make a suggestion!
-Argyll