You could try these:
HP Compaq nw8240 (ATI FireGL V5000 128 MB)
Dell Precision M70 (nVidia Quadro1400 256 MB)
Both are fine business workstation computers. Should go to a very demanding taste, when price is not a problem. I estimated the performance of ATI FireGL V5000 128 MB here:
http://notebookforums.com/showthread.php?t=81414
It should be slightly better than ATI X700. nVidia Quadro 1400 scores about 2500 in 3dmark 05. You can check 3dmark 05 stats in the following link:
http://notebookforums.com/showthread.php?t=68910