I have a gap between the headboard and the dog box, its where I fit all my water and fuel jerries. The fridge is in the front left of the dog-box and the tool box in the front right.
Chassis hasn't failed yet, only 200000km, so there is still time.
For the pantry, I use stackable 30L plastic tubs with clip on lids. You can fit a fair amount in them, but still be easily handled by one person to drag them out or stack them in the back in or leave just them out as they are weather resistant and animals can't get in.
Upgrade will be a drop down fridge slide and a single wide draw beside it so the stacked tubs can be slid out the side, just to make access that little bit easier.
I already have a ply divider down the middle of the dog box so that the kitchen is on one side and all the other crap goes on the other.