You may also look at our solutions (Cayin Technology) which connects to the network and provides for several different zones for info. Video, Graphics, Text, etc. You would need one appliance, then you would want to split the VGA signal to send it to the 2 monitors. I would be happy to discuss this with you more. If you go with a real solution, be sure that there are no license/software fees or a server is not required. Our solution does not need any special software and no server is required. You can update from anywhere with a web browser!
If you are really trying to save money, you can also simply run PowerPoint on a computer and again, split the signal to duplicate it on your monitors.
Good Luck. Contact me if you need more info.