Your running 4 cards on the foxconn mobo by using PCI to PCIE16 adapters and pCIE1 to PCIE16 adapters? No issues in getting software to recognize any of it? If heat wasn't an issue could you run 4 6990s in it or was my local computer shop right that better cards must have good mobos and processors in order to work??
If you want high megahash per dollar your looking in the wrong place by choosing a 6990. Depending on how much you pay they tend to give 1-1.25 megahash per dollar before you even add the other parts into the cost. Most 6990 builds tend to be less then 1 dollar per megahash after you include the parts.