GTX560 is probably a bad move for a gaming build, bearing in mind that if its most important function is gaming at high resolution you will probably want a better graphics card, that said you can also probably dial back on the CPU, an i7-2700k is a solid CPU but if gaming is what you need then you are better off evening out your CPU/GPU rather than a great CPU with a generation old mid/low range GPU.
For gaming I would recomend this if your heart is set on nvidia although their prices are a little higher than ATI equivilent at the moment. As for your CPU I would probably recomend this as it is definitly sufficient for normal gaming where most of the pressure is put onto your GPU
also for performance an ssd would do you wonders assuming your not storing large amounts of data.
Is there anything else that i should add to it? also should i put a cooling system on it? if so what kind?
Is there any operating system i should get and what would be a good quality monitor to use that wont cost me an arm and a leg.