Well I just got a Quadro FX5500 with 1Gb from an HP workstation and I tried (and miserably failed) to install it with 10.5.8. I got it working without QE/CI as expected but I cannot find any ROM for FX5500. I managed to get 1920x1200 resolution with NVInject and some kext tampering but thats all.
Any suggestions? I have tried to flash it with a 5500 512Mb but it didn't work (garbage screens from boot, as I was expecting) so I reflashed it back to it's original.