*Just edited this to include some more info*
Here's my drawer setup nearing completion. As you can see I've still got to carpet one side panel, finish off the edging around the entire unit (for protection and looks), fit the fridge-slide, paint the left panel where the fridge will sit, and carpet the insides of the drawers. Then I've got to buy some fittings like handles, locks, tie-down points, etc. There's still a bit to do anyway! Haha!
The large top drawer is for cooking stuff. It's partitioned to hold my stove, cookware, utensils and other things, and I'll be getting foam custom cut to hold certain items like the stove securely/not move around. The other drawers are for anything really...food, recovery gear, clothing, camping gear, etc. It all depends on what kind of trip I'm doing!
The unit's been designed to fit in with my cargo barrier, which meant that the unit had to be a little bit narrower than the full width of the tailgate, but that suits me...I need the right side clear for the sub-woofer anyway, and there's still some space on the left for smaller/easier to pack items (like chairs and my table) near the amp. Given the straight back of the drawer unit, and the cargo barrier following the angled profile of the rear seats, there is a void of space behind, which will hold a second battery and a power inverter at a later stage, and be accessible through the open area behind where the fridge goes. It will be mounted to a false floor which will be bolted down. I intend to keep this in the vehicle, but it will be removable should I need to (unlikely as my housemate has a ute!).
It's been quite enjoyable making it, and has cost me roughly 1/3rd of what I'd pay for something similar from a manufacturer. The added advantage over them is that it's made exactly to my needs.
I don't profess to being a great 'chippy', but as they say, measure twice and cut once. Think things through and it's not hard making your own storage system. The only tools I used were the saw-horses, a handsaw, a hacksaw, mitre box, cordless drill & bits, rubber mallet, tape measure, stanley-knife, sandpaper, and a paint brush...nothing fancy.
Here's a couple of early pics:
And a few of how it is currently (the bottom drawer is pushed up because of the uneven surface of the saw-horse btw):