Gigabyte has recently released the GA-E7AUM-DS2H. This mobo is powered by Nvidia's 9400 chipset. A desktop version of the 9400m chipset found in the new unibody revisions of the Macbook/Macbook Pro. This baby supports Hybrid Sli as well as 16GB of DDR2 ram.
The specs are very nice...
Chipset : Nvidia Geforce 9400
Audio: Realtek 889a (Fully supported by OSx86)
Ethernet: Realtek 8211CL (Not 100% on this, but should work)
Video: Geforce 9400 via DVI, HDMI, or VGA output.
Full spec list at Gigabytes site: Here
Assuming this new chipset is supported, you'll most likely have to sport a 10.5.6 update or Macbook/Macbook Pro restore disc minimum to install.