If you have a standard workstation from Dell, Lenovo and HP and you want to add a 3rd monitor then you will need a 2gb video card that does not require a larger power supply. Impress Computers has tested numerous video cards and have discovered that the GT710 2GB video card does the best job of handling 3 simultaneous monitors without requiring a larger power supply. The video cards have DVI VGA and HDMI outputs and can easily handle 3 x 1080p monitors.
We have these video cards in stock for $79 and can install and test the card for $50. We also carry the Acer 24″ monitors for around $119 each and have the correct connections to the video card, ie DVI VGA and HDMI.
Companies that are looking for more than 3 monitors have the option of going with a custom build PC that has multiple PCIE slots and can handle 2 video cards that have the capability of handling 3-4 monitors each. This way you can have 6 to 8 monitors on one computer. Impress Computers also has multi monitor stands that can support all monitors.