Mine is EA air assist, been on 15 years now I think, twin analogue gauges with 2 x shrader valves and button switch for air compressor mounted under drivers seat. It's a Sprinter based van, same make but different layout to Phantoms. Rides line its on rails, very stable.
I don't know if they do it as a kit or not though as it was fitted by EA. Mine is recommended 3.5Bar pressure.
Original van weight was 3850 from the factory, up rated approx 15 years ago to 4000kgs but down to 3500 the last 3 years.