If i can just hook an external cd drive, it will be really easy and do nothave to worry about screwing the system.
Any thoughts ?
Even with an external SCSI drive you may still need to mess with termination, ID number, etc. I'd echo everyone else's comments to just go internal, it's only five screws to open the case, then 6 or 7 to remove the drive sled, screw the drive onto the sled, connect a cable (you may need one with two headers if your current cable doesn't already have them), remove the bay cover on the front of the case... sorry if those steps make it sound more complicated, it really isn't!