Hi LewisT! I remember looking for something similar to the busking case you are referencing about a year or so ago. I ended up having to do what CWhite suggested which was piece together my own system.
The only thing this combination has special was that the flange to attach the table stand to was built into the base of the case if I remember correctly. You could pick up a briefcase (aluminum or not) of your preference and attach the top of a breakdown able table yourself if you have the tools to do so. This would then allow you to attach the tripod stand part of the table to your case when in use.
If it is the storage, I think it was just pluck foam and you could purchase that separate and cut to size to fit the dimensions of your briefcase.
After I typed this all up I did find the website of someone who constructs (well, maybe constructed) these tripod cases for magicians, buskers, etc.
http://promagictables.com/