The Performa 578 would take a SCSI drive (not PATA) - - whatever the largest capacity in 3.5-inch SCSI might be, if you can find one.
Original Perf 578 came with 320 MB SCSI drive.
On my G4 Cube I'm using right now an 250GB but until I tried the method in this site that tricks the open firmware only 120GB was the maximum size because Cube can't have an PCI card and I'm planned to upgrade to an SSD until the end of the year and worked with an IDE-SATA adapter as well.