Some OEM power supplies have proprietary connections. What are you trying to do? What model of motherboard do you have? I'm assuming this is a custom built pc?
Then all you need is what I suggested. Either the corsair or evga psu.
Evga - http://www.newegg.ca/Product/Product.aspx?Item=N82E16817438015
For some reason the corsair is a lot more then the evga unit so just get that one.
Silverstone begs to differ.Slim cases require sfx/tfx power supplies which only go up to say 350/400 watts max.
http://hexus.net/tech/news/psu/93515-silverstone-sx700-lpt-released-700w-sfx-l-power-supply/Silverstone begs to differ.
http://hexus.net/tech/news/psu/93515-silverstone-sx700-lpt-released-700w-sfx-l-power-supply/