I went the anti-drawer anti-slider route.
I've built full on wood enclosures in back before. Things I didn't like about them was their weight and complexity especially if any 'repairs' are required from things breaking on the trails I run.
This time I went ultra-light weight. In total, I'd be surprised if my drawer setup added more than 15lbs to the back and it doubles as a sleeping platform.
The drawers are essentially a series of rubbermaid containers with lids i purchased at Target for less than $40. I have 2 long containers stacked 2 high on one side, and 4 shorter containers stacked 2 high on the other side.
If I ever decided that the drawer configuration just isn't right, all I have to do is go to Target/Wallyworld and get a different set of containers.
I even added foam insulation tape to the lids to minimize dust intrusion. Off road, they've held up very well especially since they're not just loose to fly around back.
I seriously doubt that I'd EVER go back to any kind of 'full' drawer system after this setup. It's just so much more customizable and adjustable than a drawer system could ever be.