I don't know about plug and play, but if you have access to your tanks, the SeeLevel system gets good reports. They have systems that have everything you want except only one LP indicator so you will have to add a switch to determine which tank it reads. You will have to install their transducers on your tanks, but they stick on from the outside and you can use the existing wiring.
"You cannot reason someone out of a position they have not been reasoned into"
Al, K5TAN and Missy, N4RGO WBCCI 1322
2002 Classic 30 Slideout -S/OS #004
2013 Dodge 2500 Laramie 4x4 Megacab Cummins