I went down a slightly different route about 7 years ago and got hold of an STFM 1040 with a Mono Monitor and a 30Mb Supra hard disk (only cost me £120 then). I then onpened up the hard disk and wedged a 400Mb in its place (if I could be bothered to build a case I could put them both in).
I have also just got hold of a SCSI CD-ROM to try out but I think that there may be some problems, I need to find a Hyper Text viewer to find out how to get Beta DOS working (can't read the manual).
RE: ST-1040 and HDD