powercool is only good for budget systems thats why you tend to see them £20 or less new, but evga suppose to be good, but not the one you ordered as i looked at that before and was advised against it.
i will obviously be biased here, but i have the seasonic s12II 520w power supply thats dual rail and been perfect, no issues with power or noises and it powers my 270x nicely which takes 2 6 pins, so whether the 760 uses 1 or 2 6 pins this psu would suit you nicely, even for some decent overlcocking.
mine wasnt off here, but the price is around the £60 mark brand new, but a good 450-500 be good enough, dare i say a 400 too? cx430 maybe not, i have that also which is a used item and powers fine, but i only have a 750ti in that rig which doesnt need 6 or 8 pin connectors.