Okay, I bought the gtx 285 card. But it seems like I got the wrong cables? 
Where do I connect this big 3-plug? (there´s 2 pair of them, 4 altogether). Suppose this is for PC and I need to buy a pair of 6-pin to 6-pin?
I got another problem. The 285 card will occupy both of the power connections, so where do I connect the the 8800 GT card?