Um, nothing on the 8400 requires "proprietary" hardware. RAM, disk drives, CD-ROMS, add-in cards, etc, are all industry standard. And CD-ROMs don't come in "sizes", just get the correct interface. SATA or PATA. As far as what media, you can install a CD-ROM, DVD-ROM, DVD-RW, BD, whatever. As long as the interface matches.