I've been looking for a small touch screen monitor to lay on my desk in front of my keyboard. I saw a lot of raspberry pi ones but they were either too small or the touch screens only worked with proprietary Raspian installs. The only good one I've found is this GeChic 10" Touchscreen Monitor on Amazon that, while it has incredible build quality, is way too expensive. I don't need any fancy touchscreen technologies for drawing or anything nor does it have to be particularly high resolution. It's also fine if it doesn't even have an enclosure, I can model that in SketchUp.
Just pick up one of the various cheap windows 8 tablets, not sure how you'd go about using it as an extended display, but if you just want to browse the web on it, well that's what it'll do
You might want to look to this ChuWi Hi8 Tablet It dual boots Windows 10 and Android 4.4 KitKat (I imagine an update is coming) and for a USB port you can just get this. Ends up the same price but it's a much better deal IMO.
It's a cheap Chinese tablet. Look on YouTube if you need more convincing :) I'm still skeptical but I'm gonna get one soon so look on here in a month or two for my report on it if I end up actually buying it.