Mongox, you might of mis-read what I wrote.. I was looking for a microATX with dual x16 PCIe not a regular ATX. There are a quite a few regular ATX board out there that have what I was looking for, but no microATX... But after reading the above link, there is only a 2% difference when adding 2 5850 cards on a x8/x8 motherboard compared to a x16/x16. Thanks tho.
I found the MSI 790FX-GD70 is a monster that can do crossfirex dual x16