Travel Cajon with a really rich voice.  Print so that the sound board (drumming surface) is solid, with as much infill as you dare (My print took nearly a full fresh spool at 60% Adaptive Cubic with 4 perimeters and 4.2mm top surfaces). You will need to bridge that gap hard, or add some narrow supports that you are willing to fight with for 15-20 minutes to remove.  Has large blank surfaces on the sides and back that you can use negative volumes to customize with logos, patterns, etc.