Just a note about displays: The Nokia 5110 that you mentioned is a good honest display - and cheap. It's just a little on the small side.
I haven't tried the Digole ones - they will probably be faster because the processing is done inside them, but you won't be able to use the Bitmaps/Custom fonts that you get if you use Espruino's internal graphics library.
Espruino is a JavaScript interpreter for low-power Microcontrollers. This site is both a support community for Espruino and a place to share what you are working on.
Just a note about displays: The Nokia 5110 that you mentioned is a good honest display - and cheap. It's just a little on the small side.
I haven't tried the Digole ones - they will probably be faster because the processing is done inside them, but you won't be able to use the Bitmaps/Custom fonts that you get if you use Espruino's internal graphics library.