Sleeper storage options

Not driving an International.

 

You are in luck, I am doing something similar to my tractor, which for all practical purposes is a Century class cab. I owned several IH tractors previously so I am familiar with their construction, which is similar.
I stripped out the sleeper portion of my tractor, removing the upper bunk and all fabric panels on the sides. and back The fabric panels are likely held in place by push in plastic retainers. Easy for the manufacturer to install, you have to carefully pry each one away, they will still likely tear the cardboard backing.
The cabinets should bolt to the wall. Once you remove the cabinets and wall panels you will see lots of caged nuts attached to the framework of the cab, along with the chintzy insulation. They usually have lots of attaching points not used. depending on the configuration of the cab.
I am putting up shelving and intend to use industrial strength totes, similar to the common milk crates but different sizing. I use 1.5 "x 1.5" 1/8" thick aluminium angle for most fabrication, then either wrap it in grey vinyl to match the interior, or paint it.
Dream up a design of what you think would be more practical and go for it.