That PSU is a joke. 2 SATA plugs? The 32A 12V rail?
I'm also not sure what you are talking about. The 8pin that comes with that PSU is for the motherboard. It won't fit in the 4850x2. You would need a molex to 8pin PCIe, if they even make such a thing. I don't think you should use that PSU to power that card. It's honestly that simple.
Thankfully newegg has what you are looking for. $58 shipped, no rebate. Counting the shipping Tiger was going to charge you this probably comes out cheaper.http://www.newegg.com/Product/Product.aspx?Item=N82E16817371030