Hello sandro123.
In my opinion the best choice is someone of the new ultra high definition graphic card like this:

ATi FireGL V8650 - 2GB GDDR4 SDRAM - 100-505520 => Maximum Resolution    3840 x 2400

NVIDIA Quadro FX 4500 X2 ==> Maximum Resolution up to 3840 x 2400

With some of this card in your pc you will can test ultra high resolution monitors.
This is my idea in order to solve quickily your need.

Grretings
El Hechicero