I started off with a steel breaker-box style enclosure that I got off ebay for cheap. About 1/3 of the way into the project, a buddy at work found me some control hardware that had failed our manufacture burn-in testing. Now instead of a control system run by 3 home made PIC microcontroller boards, I have a legit industrial-grade control system with thermocouple and relay modules, an ethernet port with a built-in web-server, a dedicated serial port, a real-time processor and an FPGA. That's not really important to the thread, but I'm excited.
Either way, I had to rethink my box because the new controller is much larger than the original control hardware. I went with one of the plastic boxes from Home Depot for the second time around. The point of my rambling is that it is MUCH easier to work with the plastic box than it was to work with the steel. I would hands-down suggest the plastic box unless you have a good drill press, are really accurate with a jig saw and like using a file.
