Definitely spray in, as mentioned above we had a plastic liner one that trapped water and rusted bed.
And I like the heavy rubber mat too, but I would only use mat over a spray in liner if bed is exposed. I had a mat briefly in a unlined bed ( it kept the dog from sliding around) but the mat...
Long time ago I used a NICE with large Alice (actually the Tactical Tailor MALICE with a bazillion extra pockets), it handled loads much better than issued Alice frame. FILBE as mentioned above is cleaner outside package, but still has option to add pockets.
edited, I just saw robcollins...
Similar concept to Decked Drawer system mentioned above, I have seen several versions of a home-built raised sleeping platform with storage underneath. Plastic tubs are often used for gear, but some people build elaborate pull out drawers like Decked Drawer commercial system. Benefit is you...
This is my daily driver & hunt truck, 2012 Frontier PRO-4x Off Road.
Has pretty good off-road manners for a driver.
I am looking at adding a ARE or Leer topper this year, maybe just for trips. The short bed is a little short to sleep in comfortably, but would work in a storm and give more...