One little thing you need to be aware of if changing out the CD-ROM drive - the 6x and 8x units actually use a notebook hard drive connector to connect to the adapter board, rather than a notebook ATAPI connector like 95% of notebook CD-ROM drives out there...in my experience drives with this connector are quite hard to find. I managed to find one for my 1400 - a Hitachi unit out of a ThinkPad cicra 1997, however I'm now realising that I can't find any drivers that will make it work under OS 9. All I can say is - good luck!

For what its worth, the 12x unit, on the other hand has a standard notebook ATAPI connector...drivers allowing this will make your job a whooole lot easier