Dust, dust... *cough* *cough*
I found this interesting thing... It's an open-source wideband O2 sensor controller, which uses an AtMega8 as the brains. They even provided the source code! Provisions for heater circuit and Nernst cell PID controllers are provided, as well as input signal processing and narrowband output simulation.
I may be able to adapt this controller to control 4 different WBO2 sensors. If this is possible, then I may be able to fool my Magnum's engine computer into going to 16:1 AFR for cruising.