dealextreme links already i gave ,
even simpler one is wii remote (1500Rs, only remote needed not wii full box) and a free software .
All you need to do is to mount the Wii remote at an angle facing LCD,setup the free software,add bluetooth dongle (may b 100Rs) to pc usb port.
Go to 3.05 min in the video,here it is shown how laptop screen becomes a touch screen
Make your PC/LCD/Projector screen a touchscreen with a Wii remote - CNET Asia Blogs: reHASHplus by Michael Tan, Singapore
For display part setup display for 2 screens
option 1)if you have usb LCD ,set dual display in control panel
In case you want part of screen to be displayed also check
display link Software
option 2) you have vga input only on extra LCD ,use a vga splitter