I have a first generation dual 1.8 GHz G5. I'm wondering if I can swap the "SuperDrive" in it (PIONEER DVD-RW DVR-106D) for a later "dual-layer" writing DVD reader/writer. If so, do I need to get one from Apple as a replacement part with Apple firmware, or can I just buy the DVR-117D or other internal drive from a third party. Thanks so much, Jim Robertson --