It came as a suprise to me as well that the PowerEdge 600SC doesn't come with an on board SCSI controller. The board is a plain IDE motherboard. I was fortunate enough to have ordered the SCSI controller with the (FREE!) secondary 73Gb SCSI drive.
I think that not only their customers were utterly confused but their own staff too. Or they would have never shipped such an expensive drive for free.
/Bart