Whilst looking for parts to make a flightcase, I happened across a Dutch supplier "CaseBuilder.com", who offer a rather clever website to design your case exactly as you want, and then supply a FULL kit to build it up. The case is roughly a 1' x 1' x 2.5' (30 x 35 x 75cm)
Delivery took less than 4 days from clicking "send order", and I was very pleasantly surprised by the quality of everything,.
Step 1: Design
Here's a screenshot of the design in progress.
...and the build instructions.