Like Jeff said, the ISA (pc) slots in the 2000 are passive. They aren't connected to anything . They can be used by the Bridgeboard - on the IBM side. You can then share the drive with the Amiga (slow) There was available at one time a 'Goldengate' card that just connected the Zorro to ISA so the Amiga could access those slots directly.
A better way would be to look up a second hand external MAC scsi drive and gut it for the drive itself. ..