The san diego should overclock fine. But you could go witha cheaper 7800.
http://www.newegg.com/Product/Product.asp?Item=N82E16814143036
it's at higher clocks too...
I've done this before without a crossover cable, i dont remember how though.
Oh wait, i think i had bridged a wireless connection to the ethernet, then connected it to the other pc.
Well, now the rating doesn't really make any sense. It used to be based on the performance of one of amd's old cores, now it's just a number. The 3000+ overclocks very well.