Use this one. This is the setup I use because it has a variable dc output which helps in HW errors and overclocking just don't go past 13vdc. or if you do its your own fault don't blame me for it.

http://www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?langId=-1&storeId=10001&productId=694911&catalogId=10001&CID=GOOG&gclid=CJ_bztjlwsoCFQEoHwodF6wD0g

You Can Get the wires here... this is the same place I got them you will need 3 sets they come 4 or more.

http://www.gigampz.com/store/p7/6-Pin_PCIe_to_Bare_Wire_Cable,_24_Inches_(4-pack).html

just wire yellow to V+ and black to V- on the PSU and that's it. then wire the AC power cord to the input of PSU "makes sure its correct there is color codes for every country.

I use the RSP-1500-12 for the S7 and the RSP-750-12 on the S5 and I like the variable output dc option really helps.

thank you phil for putting me on to these they work great.