I want to get the HD 4870 from Radeon but im afraid it might not fit my Dell E520 case. Preferably, this card is the one im looking to get. http://www.newegg.com/Product/Product.aspx?Item=N82E16814121290 Will this fit my system? If not, then will this one? www.newegg.com/Product/Product.aspx?Item=N82E16814121276 If you happen to own a E520 case or know from past research or something, please tell me!