I similarly had / have an A1200 with the blizzard 1230 acc and SCSI Kit IV. I bought a SCSI box fitted with my first ever SCSI HD (1Gb Quantum) and first CD ROM Toshiba XM5701. The hard disk and the drive works fine till present date! I never had a single issue with them during my 4-5 years usage, since I discarded the A1200 in the box-room. I have then plugged the scsi box with HD/CDrom to an EMU sampler e6400 and again they did the job till 2002 when I stopped composing music. However, whenever I switch on the unit for nostalgic purposes, they still work fine.
On the PC, where I used IDE, I have thrown away some 3 IDE HD and 1 CD-Writer. From m yexperience, its either they used to built better devices 10yes ago, or it's becasue of SCSI technology.
On a different matter, SCSI I devices with the 50 centronics are pretty rare, old (2nd hand might turn faulty) and expensive, so IDe might at the end be the most feasible choice.
