I don't know which one is better and can i upgrade to sapphire 7770 graphics card?
-> http://www.newegg.ca/Product/Product.aspx?Item=N82E16883227392
-> http://www.newegg.ca/Product/Product.aspx?Item=N82E16883229285
-> Graphics Card http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=2042277&Sku=A271-7770
-> http://www.newegg.ca/Product/Product.aspx?Item=N82E16883227392
-> http://www.newegg.ca/Product/Product.aspx?Item=N82E16883229285
-> Graphics Card http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=2042277&Sku=A271-7770