You may want to consider getting a new psu , 750w would be good in case you decide to get another 560Ti for SLI.
SeaSonic M12II 750 SS-750AM 750W ATX12V / EPS12V SLI Ready 80 PLUS BRONZE Certified Modular Active PFC Semi-modular Power Supply
Antec High Current Gamer Series HCG-750 750W ATX12V v2.3 / EPS12V v2.91 SLI Certified CrossFire Certified 80 PLUS BRONZE Certified Active PFC Power Supply
CORSAIR Enthusiast Series TX750 V2 750W ATX12V v2.31/ EPS12V v2.92 80 PLUS BRONZE Certified Active PFC High Performance Power Supply
$104.99 and a $15 rebate makes it $89.99http://www.newegg.com/Product/Product.aspx?Item=N82E16817139021
Any of the above would be a good choice if you have plans on picking up another 560Ti , if you don't then you can go with a 650w of the same brands.