Welcome to the forums, newcomer!
All you did was post the makes and models of the GPU's, you didn't mention their prices and you didn't mention the make and model of your PSU either. If your PSU is more than capable of delivering 750W or more power to the entire system and is reliably built, then you can look at either of the XFX cards(look into their requirements tab). If your PSU can only handle outputting 650W of power to the entire system, then look at the Powercolor GPU.
Mind you, key words, here are the cost of each card, the make and model of your PSU and it's age. You might want to also include the make and model of your case since clearnace can and will be an issue.