I'll throw in for the airbag system but suggest that if you are going to go that route, go with a system that allows for changing the airbag pressure from inside the truck. If I'm cruising down the highway I'll leave the bags at a lower PSI to provide some additional cushioning of the ride but when I hit the twisty roads I'll up the PSI to stiffen the ride and reduce rolling.
As far as where to store those extra items that could depend on how the camper sits on your truck. On my Bigfoot I have about 3" to 4" of space between the camper and bed rails which was the result of needing to raise the camper to clear the cab so I got this clearance that allows me to access the pockets in the sides of the truck bed. I can tuck my folding chairs and my dinette bike rack system when not being used (I can transport two adult bikes and two kids bikes inside the camper for longer road trips where I want peace of mind knowing things aren't falling off) into the sides of the bed of the camper using the side access. Note that many campers have door access to the sides of the bed from the inside but that isn't the case for Bigfoots so being able to still tuck items into the sides from the outside was a big side benefit to having to raise the camper. I also placed two 6v AGM batteries in the front sides of the bed (camper sits between them and then used 2AWG cable to wire in series) so that freed up the battery compartment for extra storage (not much but every little bit helps). This also helped to move a LOT of weight toward the front.
Even though the Bigfoot is a basement model camper, the bottom of the camper is pretty much flat throughout the entire length as opposed to other basement models that hang low on the back end and cover up the bumper of the truck. If you have something like this then you could add a small cargo carrier into your hitch receiver that just provides a flat deck that you can strap items to. In my case if I did this (don't had the need so I haven't) the flat deck would be under the bottom of my camper but give about 18" of height between it and the bottom of the camper and 6'x2' of additional cargo capacity. The alternative to this is to add a super hitch and a cargo carrier to have the cargo carrier sit behind the camper but that adds another 3' of length behind the already extended length of the camper. The guy I bought my truck and first camper from had this setup and it was the first thing I eliminated... You can also install a roof cargo carrier system or even a front mounted cargo carrier.
I know your camper is entirely different but the point of sharing my examples is that once you get your setup you will figure out where the little nooks and crannies are to allow for storing more items as time goes by. I usually find these voids when I have one item that defies logical storage placement and ends up being moved repeatedly from place to place in the camper to much frustration. I eventually get so frustrated that I end up looking for a new place and put the item there then promptly forget about said item till the next time I need it and then can't find it...
Happy Travels and Good Luck!