Once it is installed, you can click Help then Contents and that will open up the full installation and tuning manual, which should help quite a bit.
That Classic FAST box only had 1 universal harness, then the customer would modify it for his needs.
It does have the Wideband O2 option, but it looks like you are missing the sensor. They are a little tougher to track down these days. The sensor is an NTK L2H2 model, which we do not sell here at FAST any more.