You'll need to buy a kit with the guage/wide band controller as the S300 can't control the wide band.
Then connect the 0-5v output from the guage to D14 (ECU)
Enter the software & configure per instructions supplied with guage/wide band controller (As comes with the AEM product you mentioned)
Ie: 0v = 0.xx lambda / 5v = 1.xx lambda etc