I would be interested in something like this myself.
Here is my warning to you though, make sure the touchscreens have drivers, drivers that work on a modern os! Some older model touchscreen monitors became defunct when 95 came out as the vendors didn't make new "mouse" drivers. It happened again when 2k came out.
Some touchscreens can operate on the standard generic mouse driver, but some do not, so just watch out for it.