Yes, that is the one and it does come with an Nvidia card.
I was curious if it was just the video card that makes it incompatible but it might be something else.
The Power Macintosh G5 2.3 DP (PCI-X) (the PowerMac7,3 2.3GHz machine) came with a Radeon 9600, so I think it's something else than PowerMac7,3 and if so, a new GFX card wouldn't help...
It's probably a Power Macintosh G5 Dual Core (2.3) (PowerMac11,2 with 970MP CPU).