I would also advice against a dual-linked Graphics card. MPQ is right.

Get a good (no need for total high-end) Quadcore (i7) and maybe an Intel SSD drive (Operating system and programs) and an additional hard-drive (for data/movies/projects/games of course and lots of RAM. An SSD will make your system feel much faster and more responsive, but you'll have to be a bit careful what you install on which drive. You probably won't notice it when 3DGS runs off the SSD, but you'll notice it with blender/photoshop.

I'd advice you get a decent ATI graphics card, like the HD5770 or HD5850. Be sure to get a quality power supply, not a no-name product. They break often and don't deliver what they promise.