I just ordered an A7N8X with a 2400+ and dual 256MB 400MHz DDR modules for around $375 with shipping, and the proc overclocked beautifully from 2.0 to 2.3 GHz which supposedly makes it around a 3000+ by the PR rating (and faster than a stock Barton I'd bet)
For me I chose the 2400+ cuz it was where the price break took place, and there was a core switchover around 2400 if I'm not mistaken.
256 of RAM has run every game I have ever tried, including SimCIty4 which has to be the biggest hog I have ever seen. If nothing else you can always add a second module later when the $$$ is a little more available.
Last thing I will say though is that putting the money you saved by buying a 2000+ towards a sweeter graphics card will probably make the best gaming system. And if you buy a Barton compatible mobo, you can upgrade just the CPU later when they are cheap as sin.