Is it a desktop or a tower?
If it's a desktop just buy a regular cheap ATAPI IDE CD-ROM or find some old used one. It should work just fine. No need to get the fastest possible though, the bus can't handle the speed anyway, unless there's a faster controller installed in it of course. Maybe get a cheap cd-burner, dunno if pure cd-roms are avaliable anymore!
If it's a tower you also have a SCSI controller. Now, I don't know if a new SCSI cd-rom will work. I've lost touch with SCSI completely since I got my 4000D myself and none of my ibm-compatibles have scsi either so...
But since the towers are quite rare I gather it's a desktop you've got.
When it comes to using it there shouldn't really be much of a problem. You need to mount the drive with a dosdriver. If you're running 3.0 or later there is one included. Not the best one so I suggest you try and get hold of a better filesystem for CD's. It works though but can't handle joliet and long filenames. Do a search on aminet for different cd dosdrivers.
Hmm.. can't think of anything else right now.
