I did a search on "Box" and didn't see anything about this but I was with an improv theater and they had simple wooden boxes painted black that were very sturdy props and very useful as many different things, e.g. benches, tables, etc. 

Does anyone have blueprints for building something like this? 

They were high enough to sit on like a chair.  I realize that this is very simplistic but I thought I would throw it out there as there may some very specific suggestions on how to proceed based on all the experience out there.  They did have cut out handles too.

Thanks!