TBC isn't needed if you're pulling from a modern digital source (DVD player, DV video camera, etc). I think you'd still need one if you had more than one video source, but configuring that has never been clear to me - even with manuals.
When setting up my Flyer, I managed to find 3.5" external SCSI enclosures for dirt cheap. One drive in each, and all is well. Only downside is that the enclosures only take low-profile drives, and it seems like most SCSI drives tend to be taller.