John, there are only a few SCSI drives the support multisession Photo CD's,
but that should not be a problem. All you need is ONE! It seems that the
Toshiba 3401 is the drive of choice for a single platter or the Pioneer 604
for a 6 disk changer with a 4x transfer speed. I'm not positive if the 604
is multisession, but I do know it will be.