Power help

I'm getting a zotac geforce gtx 560 (Idk which one) and I have a power supply from a Dell dimension 8200. I only need to power this card but the psu has no 6pin pcie plugs. The card has 2 slots, does the card come with the 4pin peripheral to 6pin pcie plugs, and do I plug 2 6 pin plugs into the card or is one extra? I can get the 4pin to 6pin adapter if I need to. I'm not really putting this in my computer it's an external graphics processing unit, it is much different (and harder) to install it externally. Powering should be no different though.