Main purpose is for multi-part solidworks builds with an upwards of 100 parts for the local FIRST robotics team. Dual monitors are very likely to be used as well as multiple instances concurrently. I was thinking maybe one these:
I have heard i the past that the GTX 670 is also pretty good for solidworks and it can be had for about $340
This kind of stuff really isnt my ballgame, I have never really dipped into work station optimized builds before
More aboutgraphics card solid works
V5900 > V5800. Pick the one that works best for your budget. The W5000 would be a better choice if your budget is in the V5900 ballpark.