Hi,
Thanks to blackwingcat, I just got my ATI FirePro V3800 working on Windows 2000... I modified one of his ATI Radeon drivers with the XP Firepro driver. Here it is, in case anyone else would be interested. It has the HDMI audio + video driver as well as the Catalyst engine... I believe Catalyst requires .NET framework 2.0.
List of supported cards:
Link again: https://drive.google.com/file/d/1bH0_LwIaGFF0VNOpHY-BipyskhMTDIJE/view