These are easy to install and very sturdy...and they have a low profile when not in use:
https://smile.amazon.com/gp/product/B001TJ50N8/ref=oh_aui_detailpage_o04_s00?ie=UTF8&psc=1
Depending on the wall structure of your storage area, you may need to back them with plywood or a block of wood on the "outside" of your storage space. I used mine for another purpose, but I installed them with #12 stainless screws and I used Gorilla glue in the hole and on the threads to prevent vibration and strengthen the bond.
Another option would be through-bolts with "fender washers" on the back side. Use 1/4" - 20 bolts and nuts with nylock inserts. Fender washers are available in both steel and nylon, and they do a great job of distributing a load on thin-walled materials.
I used an arrangement something like this attached to my aluminum pickup bed tool box to hold cargo in place. I've used mine to hold a snowblower, concrete mixer, propane tanks, and so on. They are surprisingly strong and effective, because if things are held in place and not allowed to build up "momentum" it doesn't take much to keep them still...especially holding against "acceleration" forces. Since all objects are braced against the tool box, deceleration forces are kept in check, because the objects have nowhere to go.
Carpet is a good idea as well, but a soft rubber mat might be better.
https://smile.amazon.com/Floor-Tile...=1-1-catcorr&keywords=soft+rubber+floor+tiles
There are much less expensive versions of truck bed cargo retention pipes. This illustrates.
https://smile.amazon.com/Ratcheting...9-spons&keywords=truck+bed+cargo+holder&psc=1
They mount between walls with spring tension and keep things from moving about in a pickup bed.
Bungies are probably all you need to hold the cargo against the front wall of the storage area. Use plenty of tie-downs relatively closely spaced because side-to-side motion will be the real enemy to keeping things secure. Lurching over pot-holes, curbs, drain culverts, etc. will create the greatest forces, and those will be side-to-side far more that fore-and-aft.