Looking for CUDA+graphics hardware. "Small desktop" Looking for cost effective "Small de

I have a mac mini with Geforce 320M. I would like to hear about recommendations of cost effective Mac mini alternatives for Cuda(4.0)+Graphics.
I need to run windows 7 on the machine, and it should be of about the same physical dimensions of the mac mini.
I saw the eee box, but I thought it’s GPU is much weaker than the Mac mini’s GPU?

Thank you,