You could run that system on a good 550W unit if you dont plan to SLI in the future, so a 650W certainly wont be pushing your luck. I would look into the Seasonic S12II 520W unit or the XFX 650W unit as alternatives.
Im actually going to go with the next step up corsair its a 650w for 5$ more. Really don't have an intention of getting a second card and ive actually have changed a few components now but they shouldnt require any additional power.
Oh that is nice, only 30 watts lower but $20 cheaper means i can save a little cash. Silly question, but the corsair says its compatible with the i7 the seasonic does not. Im sure its fine but i thought i would mention it.