That's a great idea.
All in pedal-pi is coded using C and the BCM2835 libraries, so it would be ideal to use a display that somebody used before with this libraries. It will make your life easier.
I have seen people using the SSD1306 displays, a popular option: hallard.me/adafruit-ssd1306-oled-display...er-for-raspberry-pi/
But I am sure that there is plenty of alternatives out there.