The pcd-60b is standard floppy width. You should be able to fit it inside(assuming length clears).It can replace scsi2sd and should be faster. but it seems you have external case on the 3000,and it would be ideal external and you could get to all the slots. If the slot in the 5.25external case is free, just get a 3.5 floppy to 5.25 bay adapter. i don't see why you couldn't keep the floppy and add a gotek if you care to.
