why do you want a touchscreen monitor, they're pretty much pointless in my view at the moment as there aren't any apps that can make use of them, now the cintiq is a different beast as thats pressure sensitive etc.
Also that screen is only worth about 200 quid before the touchscreen layer adds another £150 on top, is it worth it - not really, wait a few generations for it to come down and the apps which would make use of it to come out.
Also think of the rsi you would get working on a monitor, you need it be able to lay flat or ateast closer to a table height for it to not kill your arms, then you've got smudges which I hate on a screen.
I would consider a multitouch tablet like the dell xt range and the upcoming asus eepc t91 mt (I think its that) as they're more suited to using your fingers on but they still suffer the lack of real apps.