Gigabyte makes good cards. Those are both reference models so the cooling isn't going to be much different.
EVGA has a little better reputation, my 260's are EVGA.
But they are not worth 80 dollars thats for sure.
If you really want to spend the extra money just to have EVGA then at least get this...http://www.newegg.com/Product/Product.aspx?Item=N82E16814130550
Although thats still way
overpriced, I wouldn't pay more then $275 for a 470.