I installed mine right where I have my level gauges attaced to my Truck Camper. I use my airbags to do the "Final Fine Tuning" of leveling my truck canmper. That way I can stand in one place and watch the Bubbles move left or right, front of back, where needed.
I also did not mount an air compressor, as the type of compressors that are available are not very dependable IMHO. I had two fail, in previous truck/race trailer combinations, as well as two other failures with other racers in our team trucks. I have an onboard compressor that I use for many other things, bike tires, float tubes, rotating truck tires and filling them, checking trailer, Motorcycle, truck tires, so that is what I use.
I installed mine right where I have my level gauges attaced to my Truck Camper.
That sounds like the best idea. Definitely do not put them at the rear plate if your camper is longer than 8 feet. I put mine just aft of the rear wheel pointing down from the fender so that I could see the height at each wheel but it requires taking your hose or pump to the other side. Eventually, after about 12 years, I installed a dual gauge controller. It's not a necessity but it certainly is nice to have.
One obvious warning on the routing: Make sure the lines don't contact or cross any semi-sharp edges such as the bed seams or such. It will take a few years but they will eventually wear a cut into the plastic line and create a leak.
Ask me how I know.....
1994 Lance 990 on 1997 F350 PSD Dually "Rhino Haunches"
Why dont you install an in-house air compressor and switch panel to operate from the convenience of the cab. They sell kits with 12 volt compressor and switch panel. Make sure to get the double switches so you can operate the bags separate from each other. A little more work to install but well worth the convenience.
Nice set up.
Manual set-ups especially with no in-cabin gauges are risky we learned the $$$ way in our MH.