I've seen SCSI adapters of many types - SD card ones as well, don't have any direct product I could link, google pulled up many avenues - including this: https://www.crucial.com/usa/en/upgrades/sgi-%28silicon-graph... though didn't see SGI on list, so hard to rabbit hole that one without using live chat perhaps and may well be a legacy placeholder that time forgot.

Though network booting and storage may well be an easier avenue and cheaper. If you already have a NAS, that may well be the easiest path.