A lot of electrical/electronic engineers just do not understand how hard the packaging can actually become. Take that from an electrical and mechanical engineer. So, your question is greatly appreciated. Finding a ready made box that fits your dimensions is hard enough. Then you have to cut out certain portions of the box to fit your needs. There are a lot of box manufacturers, but if your project is very complex and the equipment is expensive I would highly suggest creating your own packaging. This can be easily done using autocad and talking to a sheet metal shop (not a machine shop, they're different). In the past when I had to design my own case I would do just this, but usually U.S. sheet metal shops charge a hefty load for onesees twosees. So, now I go outside of the U.S. and the quality is almost as good. As U.S. products are always the best (of course I am biased I live in the U.S.)! I just started using http://www.protocase.com and they are extremely cheap (they do silkscreening, custom cutouts, powder coats, just to name a few), but you might find that you have to talk with them as their software just is not there yet. They are a full fledge sheet metal shop, but their software does not imply this. For example, you can have a large 1/8 inch thickness aluminum plate with PEM studs, powder coating, and silkscreening, but their software does not allow you to specify the thickness of the metal or to have rounded corners. They will however, do it if you request it and it does not cost anything extra except for the material. There is even the option of getting a Pelican case and making a face plate for the briefcase style equipment. However, you might consider buying a pre-made box if your equipment is small enough and does not require a lot of rework, especially if it is homemade. A lot of the guys here will tell you, Newark, Mouser, Allied, http://www.rose-bopla.com , http://www.elma.com , etc. You could go so far as using extrusion that you can buy online if you feel like doing some machining.