SCSI to SATA?

[LoadWB]

There are 68-pin SCSI to SATA adapters out there.  There is no need to go through IDE as an intermediate.  I have no experience with the 68-pin variety so I can't advise you as to which will work best.  I do have a 50-pin (narrow) SCSI to SATA adapter running an SSD in an old Sparc-20 clone and it works very well.

[LoadWB]

FWIW, Vesalia sells the ACard 7730A.  http://www.vesalia.de/e_acardsata.htm

The ACard stuff is top-notch, and I would assume they've tested it.  I have a 7730AS running a DVD drive attached to my MKIII.  Note, the AS and A are different: the AS will run optical drives, only.

EDIT: Correction, the AS is a different series, but the same holds true.  I have a 7732 which is ODD, only.  In any case, I have not used a hard drive with the ACard on an Amiga.