What you linked to is just a touchscreen overlay. You put that over an existing monitor to make it touchscreen.
If you're looking for the entire package, then what you will be looking to buy is this.
For the best definition, you want a VGA TFT.
Here are some quick definitions:
VGA - Video Graphics Array - for the best definition, get a VGA input. Not composite/svideo
LCD - Liquid Crystal Display
STN - Don't know what it stands for, but aka Passive Matrix. Low viewing angle, poor colour representation
TFT - Thin Film Transistor - Aka Active Matrix. High viewing angle, good colour representation.
When buying a display for text/GPS use, make sure you get something that says VGA and TFT, and avoid anything that says STN or doesn't have VGA