If you don't plan to overclock the CPU then the 2700K is no better than the 2600K and you save around £30 that way... just an fyi.
If money is not an object for you then this point is moot but... I don't think "waiting to play new games" with a single GTX 580.. well it sounds crazy to me. I play the newer stuff with a GTX 460 and I'm getting decent enough FPS. Not maxing games out, granted but they are more than playable.... and that's with an i3-550 CPU (so some performance gains may be seen when I install my new 2600K later today ^_^)
For example with this setup I can play BF3 on high settings with some framerate issues but it's playable and looks gorgeous.... so i think with a single 580 you'd be pretty safe in most newer games?