For a system using a single GeForce GTX 580 graphics card NVIDIA specifies a minimum of a 600 Watt or greater power supply that has a maximum combined +12 Volt continuous current rating of 42 Amps or greater and that has at least one 6-pin and one 8-pin PCI Express supplementary power connectors.
Total Power Supply Wattage is NOT the crucial factor in power supply selection!!! Total Combined Continuous Power/Current Available on the +12V Rail(s) rated @ 45°C - 50°C ambient temperature, is the most important factor.
Overclocking of the CPU and/or GPU(s) will require an additional increase to the combined +12 Volt continuous current ratings, recommended above, to meet the increase in power required for the overclock. The additional amount required will depend on the magnitude of the overclock you are trying to achieve.
Since you're planning on getting an Intel Core i7-2700K, that would usually mean you are going to overclock it. Plan on adding at least 5 more Amps to the PSU's combined +12 Volt continuous current rating to handle it.
Erm, I believe it is a Corsair 700W, model number? I have no idea.
I would take off my case, but for that... I need a screwdriver. Sorry for my 'noobiness'... haha.
The Corsair GS Series GS700 is the only 700 Watt power supply that Corsair has in their lineup.
The Corsair GS Series 700W (GS700), with its maximum combined +12 Volt continuous current rating of 58 Amps and with two (6+2)-pin PCI Express supplementary power connectors, is more than sufficient to power your system configuration with a single GeForce GTX 580.