Do a search on Aminet for idefix - its there.
A tower would be ideal, but if you're adding a CD drive to a 1200 desktop, you might want to go for an external SCSI drive which would be faster, but you'd need a scsi-squirrel pcmcia connector. Having said that, some accelerators caused the pcmcia to stop working, probably not your Apollo though.
But anyway, its not going to be an internal drive on your 1200 is it, the hole is just to pass an IDE cable through, isn't it?