After considering a few "bolt-on" products that are available, what those items offer and expenses involved, I decided to look locally and see what's available.
To my satisfaction (at least for the time being), I found a Stanley, ProMobile JobChest at my local Home Depot. It doesn't weigh much (~10lbs). It does not offer the conveinience of a sliding drawer, but for ~1/8th the cost for one of the expensive units, I can live with that for now.
http://www.homedepot.ca/webapp/wcs/stores/...ll&eid=3209
Naw, it wasn't the advertized $99.95 in the link, they had plenty of them for $59.99 at my local Home Depot.
Anyway, here's a typical mess as I unstrap and unpack things after returning from a trail run, & how things look now.

Can you say sloppy?

Here's what's typically packed inside the rear cargo area of my Jeep, plus other junk sometimes. This will all be going in the box if all goes as planned, plus maybe a few other items. 5 tool boxes, 4 tool bags, fluids, 2 drive shafts, 6 axle shafts, ujoints, straps etc etc etc.

The box fits excellent in the back of the Jeep, and it's easy to tie/strap down.



Everything easily fits inside with the exception of my spare front driveshaft, but I've already solved that.


No doubt, there are pro's & con's to having one large box. For now, I'm happy to get things more organized & secured.
Having a big box, is like having a chest freezer. Nice that you can put alot of things inside, but a PITA if you need something that's near or at the bottom.
I'm pretty sure I'll divide or remove some of the items that are currently inside the box & place them in a couple new nifty Husky bags I got at the same time I picked up the box. There's plenty room behind the box & also almost a foot in front of it for storage too.
Like I mentioned above, I've been slacking at organizing & storing things better, but at least this is a start.