I ran 6-ft lengths of l-track on the passenger side of my power wagon, sitting in the lower part of the bed “ridges” and use them to secure both my fridge (ARB 73l) and cabinet unit. Drilled every other hole and bolted through the bed with big ol’ fender washers on the bottom side.
Yes, had to drill the bed… but I think it’s the most secure and versatile solution. I’ve never had an issue with cargo in/out while I have the fridge removed since stuff basically just slides on top of that track/ridges for the length of the bed. Allows for virtually infinite cargo securing on that side too.