SCSI2SD might be a good alternative. They cheap in comparison to SCSI to SATA adapters and they are readily available from a number of Amiga vendors. The V6 offers up to a theoretical 10MB/s.
This dealer can also supply 3.5" bay mounting brackets and 68 pin to 50 pin SCSI adapters if required.
https://store.inertialcomputing.com/aboutus.asp
