I appreciate the input thus far. I know I haven't posted in my own thread, but I have been reading the posts here, as well as continuing to delve into this concept.
I'm starting with a little tracked Tamiya chasis, making a proof of concept working while I'm here (deployed to Afghanistan) that I can scale up once I get home. Still waiting on some parts, but I've been able to play around.
A question that I've come up against is how, if I get this to work, to make it able to go through decon. I haven't played around a lot with electronics before, so I don't know if waterproof sensors exist, or if I could just power down the sensor board (final project will be two independent Arduinos, one running sensors and displays, the other navigation) while going through decon, and then just wait for it to dry. Everything else could be easily waterproofed.
Also, does an actual O2 sensor compatible with the Arduino exist? I don't need a dissolved oxygen sensor, I'm looking for one that says "current air O2 is 15%" so the board can say "15% is IDLH". So far my searches have been fruitless, I didn't know if anyone knew where I could find one.