Need some opinions for a gaming PC i am building

[Mastromind]

so my budget is arround 1800 euro.200euro will be spent for display( 1920x1080) and mouse.
so 1600euro for tower only.

http://pcpartpicker.com/p/1NP6g thats what i made on pcpartpicker.

my main concern is the psu..i ve been reading your forum and all kind of forums and i know that i need 700watt for 2 760 gtx and that a quality 850 watt will be more than enough but still i want to have the ability to OC a bit and still my system wont be o the verge of meltdown..so share with me your opinion regarding this and w/e else you think is wrong about my rig..

Regards

 

[Marcopolo123]

where you live

 

[Mastromind]

where you live

Greece.so i cannot use amazon newegg etc.

 

[Mastromind]

so i found a cheaper PSU ( in my country that is ) and i think better according to many reviews .
i am talking about "XFX ProSeries P1-850B-NLG9 XXX Edition Semi-Modular (Silver) - XXX Edition - power supply - 850 Watt"

xxx edition xfx is among the best psu in newegg's list..what you guyz think about it??is it a quality psu for my build??will 850 watt be enough to power my system with ~20% OC CPU and still work at it's 80% capacity to last longer?
cheers

P.S i think i ll replace gd65-gaming for a maximus vi hero too