One thing to look out for; the touch screen "type" might be important to you depending on how much that bothers you. I bought one (acer) that is optical based, which means it's moving the cursor before your finger hits the screen physically; for me, that's worse than it sounds, especially when during the spring / summer / fall the house flys come out and walk across the screen. Nothing more frustrating than a fly changing the stops on you
I don't know all the in's and out's on the hardware, perhaps others can chime in too; but my next touch screen will be capacitive, which means you need to physically touch the glass (like how most common smartphones; blackberry, apple, samsung android's etc). Capacitive are usually more expensive though.