Here are a few more choices. If you willing to spend that much, then look for a card with GDDR3 and a high core speed. Like This, or This, or This. The last one will require the space of the adjacent slot in your MB, the first choice would be the best one. Make sure you print out any rebates when you place your order, they can dissapear off the site sometimes.
edit: I take that back, the second one would be my first choice since the ram runs at the fastest, 2000Mhz.