PSU able to handle 2 way sli and a 4770k

For max efficiency and longevity (i.e., less constant load on the PSU), I'd recommend at least an 850W, but a 1000w would be better (roughly double the wattage that your setup would pull at load, and PSUs operate most efficiently at 50% load).

Obviously, wattage only tells half the story. The +12v rail amperage is important, too, since that's what will be providing most of the power.

I'd recommend this XFX 1050w. http://pcpartpicker.com/part/xfx-power-supply-p11050befx

$139 after rebate, made by one of the top manufacturers of PSUs, fully modular, 80-Plus Gold. Excellent unit.
 


Thanks!! I found this one http://www.amazon.com/gp/product/B002RWJGC2/ref=gno_cart_title_3?ie=UTF8&psc=1&smid=ATVPDKIKX0DER but i dont know if it will work, what do you think?
 


I think i will choose this one http://www.amazon.com/Seasonic-M12II-850-BRONZE-Power-Supply/dp/B00607JNIM/ref=sr_1_1?ie=UTF8&qid=1378761828&sr=8-1&keywords=SeaSonic+SS-850AM thats because i live in south america and i am ordering it from amazon, it seems to be the same as the one you sugested, thank you very much!
 


I have heard a lot of good things about xfx but i wont buy it because im looking for a psu cheaper than 130 bucks and also i want to buy with amazon so they can ship it to my country, thank you anyway!!