CAD work

[Arct1k]

The shuttle PSU's are pretty high quality although I think that barebones only has a 250 mine was the larger case that came with a 400.

The "better" quad is about $100 more - these chips's OC really well but the shuttles don't tend to have the best bios for it. You should be able to get a 10% clock bump though pretty easily.

For rendering I agree a quad will be better - my core 2 E6600 2.4ghz native runs fine at 3.25 on air.

I'd look for one of the newer Nvidia's always EVGA as there warrantee is as good as castle