Mario,
You have to watch out for that technology domino principle.
I have a three screen setup as the moment "Monitor Laptopscreen Monitor".
I have a HDMI switch or the wormhole to connect to a mac mini
Now I am so used to three screens at my desk I now want a portable monitor for travelling, with touch screen, which I would keep at my desk and have 4 screens.
Only my budget is stopping me at the moment.
Tony