Well, if you go with a 4870, look at more than just the price. While the HIS one you linked to will work, the Asus
version has a better cooler, an additional year's warranty, and more positive reviews for only $10 more.
The 1GB Sapphire
models are only $35 and $40 more than the HIS. The Sapphire has a two year warranty, but the MSI has a three year and a better cooler.