When I had my X1950 Pro I bought a Zalman VF900 for it. Cooled the mother down so much I decided I would try to do a volt mod on the card. You can probably guess what happened...Amateur soldering + PCB = DEAD
Anyways, if I can find all the parts. Ram sinks, screws, washers, etc. I will sell it to you for much cheaper then retail (which is about $40 with S&H). Let me know if you are interested.
I can testify that it works on a PCI-E version of the X1950 Pro and I don't see why AGP would make a difference.