Nice find but you won't be able to swap RAM from a beige. The Digital Audio uses PC133 memory. The power supply is also specific to the Gigabit Ethernet/Digital Audio models. ATX hacks won't work without a separate 28v connection. For AGP cards, the official Mac solution for those is the 9800 Pro Mac Edition, but be sure you don't get the G5 specific model. Other possibilities are PC cards that have been flashed with a Mac ROM. You would need at least a nVidia FX5xx0 or Radeon 9500 or higher model for Core Image compatibility. I'd pass on an nVidia 5200, though. They were billed as the cheapest DX 9 cards in their day, but were just too slow to run DX 9 games, so they likely won't do Core Image very well, either. It was more of a talking point than a useful feature in those models. You'll need at least a 5500 if you plan to go nVidia. The Altivec engine in the G4 can handle Core Image needs when a suitable GPU is not present, but better to offload the work to the video card rather than to slow down the CPU with it.