G4 towers have 2 ATA busses, a slow ATA buss to which the optical drive and Zip Drive attach, and a fast ATA buss for hard disks. If you need big cheap modern drives, you'll need to add a PCI SATA controller. The PATA to SATA adapters take away the possibility of more than one drive on a buss (no slave SATA drives), so they don't suit a server / box of drives setup very well. Unfortunately, Mac PCI controller cards are expensive. They often cost more than a used G4 computer. It still makes a good server, though. I have a Sawtooth with 2 PATA drives and 2 SATA drives which is my main data repository. The MDD has support for 48-bit LBA, so you don't need to worry about 128GB partitions.