You will probably need more than one Catalyst machine to accomplish this.
I would recommend (x2) servers, each with a single TH2G and local monitor.

The spec NVIDIA lists for this card very clearly shows the maximum resolution to be: 2560x1600 @ 60Hz
http://www.nvidia.com/object/product...00-mac-us.html

Todd is correct in stating that the general rule is to not use more than one TH2G per machine or two DH2G.
Unless you are running at vey low resolution (x2) TH2G will most likely give you problems.

Hope this helps.