So before I get into the gritty details, I should probably first cover the improvements/changes I'm planning on making on Jeff's design.
I like the overall layout of the panel, but rather than having an iPad feed random videos, I wanted to change the design so that the video being displayed was related to the button pushed or the switch flipped. Theoretically, this isn't very hard - I essentially just need a monitor in the middle of the panel in the same spot that Jeff put his iPad, and connect that monitor to the Raspberry Pi driving the entire setup. You can do this any number of ways - you can get a small TV or PC monitor and directly connect it to the raspberry pi - that's probably the easiest approach. Then in the python code simply call omxplayer in response to the switch and have it call up the desired video. The catch, though, is the size of the display. Even a small monitor will overwhelm the size of the panel pretty quickly. In my opinion, something of the 7-10" form factor is really a better fit here. Fortunately, I had an old netbook PC with a 10" monitor lying around unused that I can repurpose here.
In addition to the display change, I wanted a slight mod with the communications panel. I don't have room for a spaceship somewhere else in the house, but one of the kids can still be an astronaut and run around the house in a costume (or not), communicating with "mission control". The easiest thing for this is just simply to wire a walkie talkie into the control panel... so that's my plan going forward - bury one walkie talkie into the panel so it works via the buttons on the panel and feeds into a headset, and then have the other one go with the astronaut.
I've also got a few small tweaks that I'm planning for readouts, thanks to some items I found while shopping for parts, but I'll cover those later.
And finally, I'm not planning on building up an entire desk like Jeff, but rather make it a portable panel. That's pretty minor, though - if you're building one, this is where your creativity and needs rule over anything anyone else can design.
Next, its time to order parts.