Yeah but it's way high in price. The gts 640 shows no major improvement in low resolutions. It shows a little bit in higher resolutions, basically once you go over 1680x1050.
I'd say: 8800GTS 320MB. It's not worth spending the extra money. If you want more I'd get the GTX. With the 320MB I would just overclock it and still receive good performance.
Go w/ an evga 320 and if you have the money later step up to a gtx or a 9 series. I say gtx because the 9 series will either not be out or premium priced in 3 months.