If you do _not_ need the SCSI target disk mode but want to have plenty of storage, get a recent hdd that produces not too much noise. Avoid the old travelstar models. Consider to buy a smaller solid state disk at the prize of a large hdd.
In case you do not need that much storage, consider to grab any kind of flash memory fitting into a PCMCIA slot (like PCMCIA flash cards or any CF/SD/SDHC etc. memory card in an appropriate adapter). This way you avoid compatibility issues for CF cards on internal adapter boards. You might diconnect* or remove the internal hdd and boot from PCMCIA, leaving a silent PowerBook, the perfect typewriter. Cheap solutions are available. Example: a 1 GB Kingston Ultimate 100x CF in a generic CF-PCMCIA adapter will boot a fully blown Mac OS 9.2 in approx. 45 seconds. The required parts can be purchased new at less than USD 20.
*It is possible to unmount and shut down the internal hdd by software, but it will spin up and mount again on every wake up or boot process.
P.S.: have a look at the 68kMLA Wiki.
In case you do not need that much storage, consider to grab any kind of flash memory fitting into a PCMCIA slot (like PCMCIA flash cards or any CF/SD/SDHC etc. memory card in an appropriate adapter). This way you avoid compatibility issues for CF cards on internal adapter boards. You might diconnect* or remove the internal hdd and boot from PCMCIA, leaving a silent PowerBook, the perfect typewriter. Cheap solutions are available. Example: a 1 GB Kingston Ultimate 100x CF in a generic CF-PCMCIA adapter will boot a fully blown Mac OS 9.2 in approx. 45 seconds. The required parts can be purchased new at less than USD 20.
*It is possible to unmount and shut down the internal hdd by software, but it will spin up and mount again on every wake up or boot process.
P.S.: have a look at the 68kMLA Wiki.