I think that putting the equipment between two sheets of Lexan, with enough standoffs, I should be far enough along. The real problem is the orientation of the peripheral ports. I need to get to the USB, Ethernet, HDMI, SD card slot and maybe the GPIO from the side of the setup. The SD card slot is needed to change out different experiment setups. The others are self explanatory.
If I get it tied down enough with a sufficiently narrow width, it should work.
Update: I purchased two 8x10 sheets of Lexan from my local Home Depot, along with 6 - 1" plastic standoffs, 4 rubber feet, and mounting hardware. I wasn't able to find M3 screws or nuts but I did have some that I purchased at a different time. It turns out that 6-32 will not fit into the mounting holes of the RPi, but M3 will. I was able to take 1/2" standoffs and cut them in half with a PVC pipe cutter (does a really good job BTW). I mounted the RPi in one corner with the power and SD card slot about 1/4" from the edge; this has the SD card sticking out when it is mounted, but makes it easy to change out. I wanted to be able to get to the SD card slot for changing the peripheral. Now my issue is mounting of the other elements. I figure that I should take apart the USB hub and that should make it easier to mount in the shell. The current state of the configuration is shown in the following picture.
I am planning on mounting the USB Hub in the center of the left side in the photo (the case for the USB Hub has been removed). The battery will be mounted on the bottom. I will also mount a USB-WiFi adapter with antenna at the top. In addition, I will probably mount either an Arduino and/or a USB-Audio adapter on the left. That should cover me for most applications. I would assume that I would attach the Logitech keyboard USB dongle on the right side of the USB Hub.
Mounting for the battery and other components has been somewhat of an issue. I would like to be able to remove the battery at times since I also use it with a robot and it also acts as an emergency iPhone battery recharger. I would like to get a clamp type mechanism but I am not sure where I would find such an animal or what it even looks like. Looks like a trip to Home Depot / Loews is in order here.