8GB and a Q6600 would be nice. However: try limiting your maxfpsbk to 15, looking up the LOD macro, and maybe disabling a few non-essential addons on the drones.

Vista improves on quite a few things...I'm experimenting with XP64 and find it lacking on a number of points, so I'll probably be back on Vista before long. It's the "32" part that is usually undesirable for multiboxing, since 4-8GB is standard for the "5 accts / 1 machine" model. You're going to need to install the 64-bit version in order to get use more than the 3.375GB you can see now.