So I got I/O's "ArmTracker" software, and piped it into "PTS". Then using Grifu's "Stringless" remote control script for Unity, I as able to read in the data and remap it to my own temporary IK chain.
The performance is a bit sluggish, and I'm sure it'll improve over time. That, and the fact we're running off an old mac laptop.
Next step will be to incorporate a real Virtual Muppet Character test, to this proof-of-concept workflow.