Dan you will like the rotarys, 2mm perspex should be okay, I use 3mm myself, but my design is bigger and so needs to be more rigid! You can run the usb cable for the SLI_M thought the wheel! Much tidier, I will show you how later in a tut! (you guys are racing off doing all sorts, I cant keep up lol, good stuff!)
DAN Buy the 3M carbon film, others are a bit cheaper, but pants in comparison, trust me, I have used most types!