http://www.mars-tech.com/aec-7720u.htm
These things go for cheap on eBay all the time.
These things go for cheap on eBay all the time.
No Mac ever had built-in ultra-wide (68-pin). Wide SCSI wasn't even out till 1994. An ultra scsi (50-pin) adapter should work just fine though, the Mac will simply run it at the old SCSI-1/2 speeds instead of Ultra. Parallel SCSI protocols have always been nicely forward-backward compatible, you just have to adapt for the physical connectors.