Core duo is the best cpu around at the moment, but turion x2's are not bad at at all. Depending on what your budget it is, you could either go for dedicated graphics module or integrated. ATi has some decent integerated solution's kicking around at the moment, a lot better than Nvidia had. If you're going for something dedicated, I'd head for Nvidia.
Dabs, Ebuyer, Komplett, blah blah.