I am not sure what the pricing is by you as I am from RSA, but go for as good as you can get. I am guessing that $ 20 more could get you a 6870 which should do OK. I would not recommend going higher with that PSU that you have. I am unfamiliar with that make, so I am not sure how much it can handle. Search for some reviews on the PSU to get an idea of what it can handle. If you want to get an even bigger GPU I would recommend getting a better PSU.