Electrostatic properties of plastic enclosures

I would also choose Aluminum or zinc diecast.

If you want to make your own panel without much design knowledge, theres a company called Front Panel Express that will do custom jobs, you can download their custom design software for free, and design your own enclosure, you can even order it via the software itself, it will take more time than buying a pre-made enclosure and sending it over to Front Panel Express, since you will have to design each panel of your enclosure.

Heres the link to Front Panel Express: http://www.frontpanelexpress.com/

However, my advice is to get a pre-made enclosure, you can buy several of them online, one example is Hammond Manufacturing, here's the list of the enclosures : http://www.hammondmfg.com/scpg.htm

My advice is to pick an enclosure that fits your needs, and if you want extra features or engravings, send it to a CNC service provider to be engraved or machined.