Air bags minus the pump for the rear? Complete Air noob here.

[Low & Slow]

Is it even plausible to install a set of airbags just in the rear? I'm looking to bring the bed height down about 5 inches yet still be able to pump up the rear with an air tank when I have a load to haul.

Do air bags completely replace the rear coils? Or would I need a set of springs to put the bags into?

What about the adjustable air shocks? Would I need a set of them as well or could I use a set of lowering springs and a set of air shocks to adjust ride height.

Thanks guys!