PCI SATA cards work great in pre-G3 Macs. I have used it in a 7200, 7500, and 9500 perfectly. I have also use a PCI ATA/IDE Card in a PowerMac 7600 and it works fine. I think the card will adjust to the PCI Slots.

I don't think you will have any problem with the PCI cards in those slots. I have never had an issue with ANY PCI card in the older macs. Usually they just don't want to support anything lower than a machine that can run OS X. Which is why they list G3 systems.