I have a G4 AGP 800mhz. I have two internal hd's. I see two open bays in my box. Is it possible to add more drives in there? I didn't know if there was something like a 4 or 4 disk ribbon cable to replace my 2 disk ribbon, or perhaps a pci card that sets up for two more drives...? I do video work and want to get more space w/out losing my current drives (20GB, 120GB)