It must be either an A2090, or A2090(A) (the A stands for autoboot), since the A2091 lacked the MFM-controller, but featured a 2MB RAM-expansion.
The A2091 is pretty much the same as an A3000s internal SCSI, so after checking wether both ROM and SCSI-chip are "recent" it wouldn't give you any problem.
The A2090 are different and very ancient kind of beast, forget about running bigger HDs on it and don't even dream about CD-ROMs.
Or in other word, you'll be better (and cheaper) of by getting a 2nd-hand IDE-controller and useing "normal" IDE-drives.
