Agree.
I use an Elsa Gloria 2 @ work (based off GF2 I think) and it is very fast on Pro/E. Not sure how Pro/E and I-deas are with respect to hardware efficiency, but I suspect they'd be pretty close.
If you don't plan on gaming, you can get any old Quadro card and probably be fine (I work on robots, so they are pretty small assemblies, often consisting of 100 or so parts plus 200 or so pieces of hardware (which, for some reason, our comany has extremely complex)).
For me, the P4 1.8 ony my work computer is much more of a bottleneck than the graphics card.
However, if you do game, then you will want to try either modding a gaming card or buying a higher end quadro so you can get the fillrate necessary for good gaming performance.
Also, I used my GF1 on my Pentuim2 400 and had great success with Pro/E and assemblies with a couple hundred parts.
So, what are you going to be designing? That might help us give a better recommendation for the design aspect (for gaming, you are pretty much stuck with getting a very high end card IMO, hehe).
-D'oh!