http://www.overclockers.co.uk/showproduct.php?prodid=GX-250-SP&groupid=701&catid=56&subcat=1502
This is the adapter you need, you will need two of them, even if you don't plan to use eyefinity.
Weird that OcUK don't have it under the adapter list...
So how does that fit into my mini display port?