The case I picked up from Harbor Freight. I removed the top and bottom dividers and went to work. The bottom is framed in 1/4" wood for added strength and stability. The top also has a reinforced frame.
On the outside are a video in, video out, audio in, audio out, a 5v in, and a 12v in port. The 7" monitor uses the 12v plug. Everything else is ran off the 5v line.
There are three on/off switches. One each for the Arduino, Raspberry Pi, and the audio amp. With the Arduino and Raspberry Pi off, you can switch the amp on and listen to music from the audio in port.
There are two SD cards that I keep in the case. Both 16GB Class 10 cards. One is for Raspbian and XBMC. The other is for RetroPie. The wireless keyboard I got from Amazon has a short USB extension cable. I used Velcro to attach the female end to the side of the case so I could access it easier. When the RetroPie SD card is inserted I plug in a homemade wireless Xbox 360 adapter and can play my favorite games.
The NeoPixels are controlled from my Moto X using an app that I created in an earlier project.