http://pcpartpicker.com/p/2Kx4U I havent built it yet i have some parts i know i need to replace the psu so dont rate me on that.
Could you suggest a psu ?
It is just awesome! The GTX 780 won't give you any problem in my opinion. You've chosen a good CPU as well, Haswell and K (overclockable). So yeah, I'd say that's quite decent.
I'd tell you to get a PSU from a trusted brand with 750-850 watts. That'd be enough.