I would have to recommend a nividia Based mother board built on the Nforce 590 SLI chip set (This is because I'm an Nvidia Fanboy)
and then you could pair that with one or if your Crazy 2 Geforce 8***'s
Azus make some very good mother boards , but they come at a price , if you don't have that much Cash MSI make some Very good Cheap Mother boards
Also you might want to consider one of the New Dual Core Chips , they do have an Extra bit of a kick.
Always buy the Best you can afford , but never regret , it will all be worthless in 8 months