I need a 500 w psu with a 6 pin connector for an ati radeon 7770 graphics card. I found a Rocketfish RF-500WPS2 500-Watt ATX CPU Power Supply for it. I don't know if I should buy it. Can someone please recommend me a reliable one that is in a price range within 30-50 dollars. It also needs to have a 6 pin connector. Also does every psu can fit a desktop? I have an ACER Veriton m420 computer. Do all of them fit or do I need a specific size?