Zip250 drivers are available on Aminet.
I use a Castlewood 2.2gb Orb drive (about the size of a Zip drive, but takes 2.2 Gb disks) with my A1200 and A3000. No special drivers needed - just treat it as a SCSI hard drive. It even came with a SCSI to USB adapter so I can use it on my desktop PC's and laptop too.