AME GPU mac pro 1,1 Yosemite

Hi,

I'm looking for a GFX card that can be used for render acceleration on a mac pro 1,1 that I've managed to get Yosemite working on.  I currently have a Geforce 8800GT but doesn't seem to be supported.

Any recommendations as I cant really afford to upgrade my Mac just for render acceleration.

Thanks,

ae