What's the point of a Quad core, and 4 GB of memory..... If your vid card is going to be mid range ? Just wondering. I would reccomend the x1950, i beleive the 256mb edition is in your price range.
He said in his post he only does light gaming, so there's no point in him getting anything fancy as far as a video card goes...
But I second that recommendation of the x1950, well the x1950pro actually.