I got a nice small monitor with touchscreen from a scrapped payment terminal. The touchscreen is manufactured by eGalax and has a normal USB-interface. Very nice for my Raspberry Pi. Except that it needs some work to get it working
sudo apt-get install xserver-xorg-input-evdev Add to /usr/share/X11/xorg.conf.d/40-libinput.conf :
Section "InputClass"
Identifier "evdev tablet catchall"
MatchIsTablet "on"
MatchDevicePath "/dev/input/event*"
Driver "evdev"
EndSection