We have been using these at the office for development. You can find them under different brand names as well. Screen quality is really good, an IPS 1080p panel. They do have VESA mount and pretty decent speakers. They have an HDMI port and, IIRC, support CEC. Their build quality is ok, certainly not rugged though, but their price is super cheap IMHO. And they work with the Raspberry Pi. If you are looking for digital signage software as well, check out Yodeck.