Cajon = drawer. Don't buy one MAKE ONE!!! Make it the same height as a chair so you can sit on it. Important points:
1) cut a circle in the back panel so you can put a microphone in it.
2) Fit a HINGE to the front panel so you can open it and tape different things to it. The front panel shouldn't be thicker than 6mm.
For example, I tape copper rods to the front panel to make it sound like a snare drum.