Supported videocards on PowerMac11,2

Hi,

I have a PowerMac11,2, which is a G5 that doesn't have AGP, only
PCIe.

At the moment, it only has an NVIDIA GeForce 6600, and so X only
uses wsfb(4), and that's in monochrome.  But I'd like to do more
macppc testing.

Does anyone know which videocard is known to work at the moment
on a PowerMac11,2?  AGP cards seem like out of the equation,
and I need a card which accepts a Mac firmware.  It looks like
an ATI X1900 GT could work, but if anyone knows whether it
really does, that would be helpful.

Thanks.