a generic PSU is almost always crap, and even a decent brand 350w would not be enough for your setup. I recommend something like this
http://www.newegg.com/Product/Produc...82E16817371002

The system itself is not power hungry it is the video cards that make systems need massive PSUs. Any good brand (Antec, Corsair, Sparkle) PSU of 500+watts should work for you, dont get anything less.

Crappy PSUs in a good computer is like buying the shell of a Shelby GT and putting the engine from a Ford Probe into it.