Today I worked more on the schematic design and some sample board layout designs to see just what will fit within the room I have to work with. It looks like I'll need two circuit boards to fit all the goodies I'm wanting.
This evening, I added a touch-off plate to my CNC router. This is needed to very accurately measure exactly where the top of the stock is and zero the z-axis to that location before I start cutting. With the prospect of cutting my own circuit boards, this got me off my butt to get it done. I've been wanting to do this for a few years and now a good enough reason came along. The step-by-step directions on how to set this up in Mach3 are here. Essentially, I can now hit a button inside Mach3 that will lower the Z-axis down until the tip of the endmill makes contact a sensor pad, then it stops automatically and sets that point as the zero+thickness of the sensor pad.