Hmmm Strangly enough I have herd from various places on the net you can use a old PC 720 drive as a ST internal one and also a new 1.44MB drive too just mess with the jumpers.In theroy this would work just look on the net for a good guide I cant remember where I found it but it also had info on how to make accelerors and all manner of cool cables,connectors and all sorts of home brew ST modifying.
Aha here it is ;
http://atarihacks.cjb.net/
Some is in a language other than english.But the drive info is here.
RE: Disk drive