-Raspberry Pi with all the fixins (sd card, keyboard, mouse, ethernet/wifi, preferably a monitor)
-and then one of these two: (the pi lcd plate is easier for beginners):
---raspberry pi lcd plate (http://www.adafruit.com/products/1109)
---or a lcd shield (http://www.adafruit.com/products/772) and a logic level converter (3.3v to 5v, your choice.)
install Raspbian on your pi if you dont have it already. there are many great instructables for doing that.
Set up I2C as described here: (don't do any of the libraries yet) http://learn.adafruit.com/adafruit-16x2-character-lcd-plus-keypad-for-raspberry-pi/usage
then download this whole gist from github: https://gist.github.com/red-green/6118462/download (sorry the name is messed up)
to edit the list of products it displays, just type nano sfestock.py and use your arrow keys to navigate to the line that says
productid = [11546,11868,11589,11021,11286,9716,11215,11712,8938,709,569,8653]
You can edit those numbers to any IDs you want. seperate each one with a comma.
if you know a bit about python programming, you can change the api it uses. minidom is a great XML parser and the CSV library also is very useful.