Need your opinion in building a computer for work only - photoshop/3d

hi everyone
couple of months ago tom's hardware had a 4 days of system built marathon

http://www.tomshardware.com/2007/05/11/system_builder_m... .html

in there as most of you know there were three categories:
the low price, mid price, and high-end system.

in that marathon they mentioned that they built those system to handle games
and there will do a specific marathon in the future  
the computer I need is really specific, it does not aim for any games.

the only thing it needs to do and do it as best he can, is run various graphic software's for image manipulation (large raw formats), 3-D modeling and rendering, video editing.
I'm striving to build a computer that will be dedicated to work only.
I'm thinking more in the range of them mid price system, my budget is not so high it's more of a student budget

what would you change in that system, that it better fits my needs?
Would you have left something out?

Your opinion matters, I regard you as professionals
Thx David