Antec eco neo 520 vs Earth watts 500

Fans don't take much. You have a 45nm CPU so even OC'd I doubt you'll be much higher then 125W. For easy math however we'll use that number. Toss in 175 (again a number higher then you'll actually use.) for the GPU your looking at 300W for the biggest things in your system. Even if your mobo, ram, and fans took another 100W, your now at 400W. 400W / 12V = 33A which your PSUs can do. I'd still take the Neo.