I got my system from cyberpowerpc about a year ago.  Its a quad system, I put vista64 on it with 8 gigs of ram (put the ram in myself after market was cheaper, but went with fast ram) and a 8800GT  though for the same you could now get more computer for the same bang.  They are nice you start with your basic and configure everything (though you have to watch your own, that would be nice addonitis ).  I haven't had any issues.  Start with one with free shipping, then adjust in the configurator, it will say core2duo but you can change the MB and Processor in the selection.