I'd get an Intel i7 or i5 quad core CPU, with 8GB of RAM (2X 4GB sticks) and room to expand to 16GB+. I'd get the fastest video card that is passively cooled you can get, that also has 2 DVI outputs (or some use DP or Mini DP for the second output, that will require a dongle to get the second DVI port) and that has 1-2GB of RAM on the video card.
I'd get Win7 64bit if you still can; rather than Win8.