The PB180c should not be too picky about the kind of SCSI drive, as long as it meets the form factor. As it belongs to the 150 there might be several issues to avoid. Try to find a list of "positive" tested drives. An IBM laptop drive seems not to be the best choice, in my opinion. Any older IBM or Hitachi laptop drives I noticed, like Travelstar, were very noisy. If you want to have some fun with that computer check for a recent drive that might be compatible.