Dual View, 2 times the same screen

Hello, I have a syncmaster223BW.
It has a nice display of 21.6 ".

I would like a know to achieve the dual view by buying a new screen:
Should I take the same screen? (it is found and not too expensive)
Should I take a screen of the same size of a different model? (differences in pricing?)
Should I take a larger screen? (Imbalance of vision, better resolution, graphics card will follow to 1680 + 1900 resolution at the same time?)
I have a HD 4850 graphic card, not for playing games, but for more usage of photo design. If you could answer about the color profiles it would be nice. Thank you

The ideal is to take the same screen, pixels are the same size, same color, etc. ... It will make you an Windows office by 3360x1050. Otherwise, the HD4850 is a pity if you do not play games ....
:rolleyes:

Thank you for your opinion. It is true that the most correct way is to avoid the hassle of colors.

even with two different screen resolution it works, I have a screen resolution of 1280x800 and the other a 226cw.

You can take the screen as you want. But necessarily for the same color rendering it is better to have 2 identical monitors, as it is the screen which is solely responsible for this. That said you can have the same record with 2 different monitors through a phase of calibration (which is, in my opinion anyway required for an LCD screen)