Price (and to a lesser extent, weight) considerations aside, I've dreamed of a full Zarges or Alubox aluminum box setup. Zarges will even manufacture custom size boxes for you, if your pockets are deep enough:
zargesusa.com
I love the "idea" of Pelican cases, but in practice, they are just too damn heavy, and don't use volume very efficiently. Somewhat cheaper options that are still fully waterproof could be the modern "modular" tool boxes from DeWalt or Milwaukee available at any hardware store (the Milwaukee sets would probably need to be spray-painted to something other than "steal me" red). Can even get boxes with drawers for your cooking gear/food supplies.
The approach I used in my D90, where space is more of a premium, is to install a Front Runner rear drawer which exactly matches the height of the wheel wells. After that, you have a completely flat surface and can use any box setup you want. I've bought airline tracking, but haven't actually installed it yet.
For casual camping (and storing camping equipment when not in use), I've found that the "Really Useful Box" works perfectly: the 60 Liter box stacks perfectly and is about as large as one person can comfortably carry and reasonably sturdy (at least in warm weather--plastic gets brittle in the cold), while being significantly lighter and cheaper than all of options above. Drawbacks are that it is not fully water/dust sealed (though can be left out overnight in the rain if needed), and is probably not durable enough for full-time expedition use (though a good bit sturdier than the McKesson style boxes you mention above).

Zarges USA

I love the "idea" of Pelican cases, but in practice, they are just too damn heavy, and don't use volume very efficiently. Somewhat cheaper options that are still fully waterproof could be the modern "modular" tool boxes from DeWalt or Milwaukee available at any hardware store (the Milwaukee sets would probably need to be spray-painted to something other than "steal me" red). Can even get boxes with drawers for your cooking gear/food supplies.
The approach I used in my D90, where space is more of a premium, is to install a Front Runner rear drawer which exactly matches the height of the wheel wells. After that, you have a completely flat surface and can use any box setup you want. I've bought airline tracking, but haven't actually installed it yet.
For casual camping (and storing camping equipment when not in use), I've found that the "Really Useful Box" works perfectly: the 60 Liter box stacks perfectly and is about as large as one person can comfortably carry and reasonably sturdy (at least in warm weather--plastic gets brittle in the cold), while being significantly lighter and cheaper than all of options above. Drawbacks are that it is not fully water/dust sealed (though can be left out overnight in the rain if needed), and is probably not durable enough for full-time expedition use (though a good bit sturdier than the McKesson style boxes you mention above).