IMHO I would go with a whitebox build, do it yourself or have someone do it for you, really its not hard to build one, just have your homework done. I would also have a new computer that is upgradeable in the future.
Like others said, dual core would do what you want.
On the spinning clipboard, MY computer had a problem recently and I replaced the motherboard and CPU. I went from ASUS to Gigabyte, I used to have a amd dual core and i used the optimizer patch. I have a phenom triple core 8750, i have no problems running AH, also I don't use the patch.