Yeah that's all good stuff, that checks out.
I'd strongly recommend getting the onboard air compressor if you do get airbags.
They're really a pain without it, and they're really great with it.
You want a kit that allows separate left/right adjustment.
The way they usually work is one button sends air into both bags, then you have bleed-off buttons that allow you to independently dial each down to where you want it. One way "check valves" keep the air from traveling back and forth between the left and right sides.
They even make wireless remote controls with digital pressure readouts, which are kinda cool because you don't have to install any more junk on your dash.
