Cutting the Acrylic (Plexiglass) Case
The case can be ordered from https://www.ponoko.com/showroom/ArtBIT (they are free I don't earn from the sales it's just a convenient for someone to order them). You can always use the supplied plans to cut the acrylic/plexiglass yourself.
I've used a 3mm thick cast black acrylic. Once you peel off the protective layers (NOTE: don't peel them off until you've assembled the box), it is actually 2.9mm thick, and the box plans were constructed using that thickness, and it turned out really nice.
The diameter of the lens that I've used (Titanium Super Wide Lens 0.42x AF) is 56.8mm, but the diameter in the plans is actually 56.7mm to compensate for the width of the laser beam and the acrylic that melts around it. In my original design I've used 56.55mm and the fitting was too tight, I had to sand off 1/10th of a millimeter in order to fit the lens through.
To open .dxf and .dwg files you would need AutoCAD, but you can also use DraftSight - which is a great, free, alternative.