I use a 14point7 SLC-OEM controller (on a 9A engine as well) and am happy with it. It replaced an Innovate LM-1 which still works but the connectors on it were starting to wear out and get intermittent. Initially I used the SLC wideband analog output, which was fine but decided to add a TinyIOX so I could use the I2C bus from the SLC and then CAN to my MS3. I would not entertain using a NB sensor since it offers no useful info for tuning the Megasquirt.
Personally I would stay away from all things Innovate. The LM-1 and LC-1 were good but follow on products have been unreliable and their support since Klaus Almendinger stepped away has been terrible.
