Dave,
I went to the Rolandsite to see the specs.
It says standard scsiport for external data devices, which means I would do following;
Buy a SCSI harddisk standalone-unit and just hook it up.
This way you do not need to hassle with PC settings/conflicts which might arise.
If you do not have a cdwriter yet, ofcourse the Roland cdwriter is a good option.
My opinion only;
Stay away from zip drives!
There's allways a problem and capacity/price comparison is bad as well, compared to Harddisks or cdrecordables.
Fred