Is there any difference? I want to be able to drag items across the screen and put them into position in something like a powerpoint presentation...
Well there's more than one kind of touch panel. Some are not as responsive. If you compare the touch on iphone vs a film based touch like on a cash register, it's a world apart.
I'd go with a touch screen monitor simply because it's the easiest to move around and replace. Any kind of integrated solution usually takes you out in other areas if one part of the solution dies. As for the type of screen, ASSEMbler is right. The different techs are totally apart from each other. Some are just crap and some are very good. Lots of cheap Chinese brands use the crappy one where your touch causes the plastic to touch another layer inside the screen which sucks (Forget the name for this technology). The capacitance technology is much better.
The tech in my old Treo 680 (circa 2006/2007) versus my Samsung Captivate (Super AMOLED screen circa ~2010) are as ASSEMbler put it, worlds apart. I highly suggest test driving anything before buying it simply to see how well it responds to your hands.
