And which brand of power supply is better ?
650w is plenty, if you plan on getting a second 770 down the track you will have to get a bigger power supply though.
Just for future reference, PC Part picker gives an estimated wattage on the top right corner of the System Build section.
As for Brands, most are fine, due to the components you have are reasonably high end, i would recommend getting at least an 80+ bronze power supply.
Corsair, Seasonic, are arguably the best/most reliable brands.
Thank You !!!
not a problem, good luck with your build