IIRC, the G5 Powermac can use a PCI card as an additional video card but not as a primary video card.
Look at flashing a PC Radeon 9800 Pro or Nvidia FX5200, FX5500 or FX6200. You should be able to find one under $40.
Look at flashing a PC Radeon 9800 Pro or Nvidia FX5200, FX5500 or FX6200. You should be able to find one under $40.