I have Firestone airbags with their "Dual Air Command II with 9230 compressor" (compressor, tank and in cab controls). FWIW I really like the setup and being able to check, raise or lower the pressure on either of the bags from the cab is very convenient.

What I found is that the hoses used in the air system are very stiff. This makes it difficult to run them through the firewall, under the dash, to and from controls and the gauge and limits your mounting options.

The pacbrake control you link looks very much like the Firestone control.

If I were to do it over again for ease of installation and more flexibility in mounting I would lean towards the electric solenoids over the pneumatic valves.

I ended up taking the panel apart, building a cup for the gauge (it is quite deep and has hoses coming out the back) and installing the controls in the knee panel under the steering wheel.

Good job on the research, you have put some thought into this.

Good luck,

George