One thing I might try is running the seagate by itself, and then see if you can get prepped and formatted. At least you'll remove the other drives and possible termination issues as a source of the problem.
Did you get the drive off ebay? I'm batting about 50% when it comes to getting drives I've purchased on ebay to working. The way the system just locks when it hits the SCSI ID makes me believe its a drive related issue.
