We fitted this GMC Savana work van with our OD-X backup camera system with 7" standalone screen. We mounted the camera next to the third brake light looking down so the driver can park closely to the vehicle/obstacle behind.
We also installed the Thinkware FA200 1-Channel dash cam as well for both driving and parking recording. These are very cost-effective dash cams with excellent reliability, the rear camera is weaker compared to other models but since this is a 1-channel application, it wouldn't matter.