The first round of ordered modules arrived from Digikey, and I spent the better part of the weekend testing their functionality. Most of the tests I ran on the modules were simple call-and-response, or sensor reading. I discovered a website (Tinycircuits.com) which sold, unsurprisingly, tiny circuits. These are perfect for a space limited project.
There were a few hiccups.
At first, I couldn't get the ESP module to work. I'd initially pegged the issue to be a power draw issue. After testing a few modules, couldn't get the IMU module to work as well. I later the microcontroller was damaged sometime during the testing, and was unable to communicate with some modules. Digging through drawers, I found an old Arduino Uno that I used to finish testing the modules.
I've updated the B.O.M.
Next steps are: (1) Hook everything up (2) Take it out for a joy ride (testing at least one function per module in situ) (3) Make revisions on the case (4) Write a bunch more code.