I never have any problems with my client...because, my client is my wife and she is also the designer.
White Oak (Polish)... 3 separate "boxes" so we can move them around (and if they move....) or change the arrangement.
Each box is 1 Meter (39-3/8") long...55 cm (21-5/8") high (including 2" legs) and 50 cm (19-11/16") deep.
I used dowels because for me, it was the easiest, fastest and most accurate way (I'm doweling on the router table).
The finish is stain and 5 layers of clear varnish.