Well, it really depends on what he's doing and what he's running. About the only thing that would really be useful in any case would be to get two nice large monitors- something in the 20-24" range with a resolution of at least 1920x1080. The rest depends on his particular usage. If he is doing a lot of heavy rendering and visualization with programs that cost as much as a nice car, I'd suggest a nice dual-socket workstation with a professional OpenGL video card. That will probably run somewhere north of three grand. If he's doing typical CAD stuff that's routinely done in college, just about any remotely modern computer will work.