Yes, you can use the PLM as a lambda input into the M4, I dont think you even need the "lambda" option enabled in the M4 for this setup to work. The PLM manual has details on the connection and settings.
Alternatively you could use any other wideband controller that has a progarmmable analog output such as techedge, 14point7, etc (I wouldnt bother with innovate). I think the M4 lambda input will only take 1.2V max.
Also, if you already have the lambda option enabled in your ECU then oxygensensor.net is a good source for the old LMS11 4 wire sensor.