Although the chipset supports dual displays, the specific card you have may not -- even though it has the additional connector, there's no guarantee it's active. But even if it is, as you've discovered, finding the right bracket & cable is a real challenge.
It's likely a lot easier to simply add either another low profile video card (IF you have an available slot) or to add an external USB video adapter to support the 2nd monitor ... something like this:
http://www.newegg.com/Product/Product.aspx?Item=N82E16815101001