Hey Brian. If you're looking for divider ideas, look here..
http://www.rrcases.com/trunkoptionstackdivider.htmThe bottom two pictures show R&R's divider options, which are quite nice. Depending on how many sections you need, you can just move around the dividers. Three sections, two sections, or one big open trunk, the choice is yours.
How big of a system are we talking about?
If it's a small system, do you carry a distro & feeder? On my small system, I got tired of rolling in a distro and 75' of feeder only to find out that I had nothing but wall outlets. So, I went with 2 trunks. Trunk #1 carries the snake, Speakon cables, and Edison AC cables. Trunk #2 only carries the distro, 75' of feeder, and anything else associated with tapping in power. All microphone cables are in a 4 drawer workbox along with the mics, direct boxes, tools, and small sub/patch snakes. I prefer the workbox option over numerous small cases for multiple reasons..
1) Easier to load in/out (one roll instead of multiple carries)
2) Easier to work out of.
3) Easier to keep an eye on.
4) More dificult to steal.
On my A rig, it was 3 trunks minimum; AC trunk, Speakon trunk, and snake trunk. All 3 trunks are 30" by 24" by 35" high. As with the small system, all microphone cables, mics, direct boxes, tools, and sub/patch snakes are all in a 5 drawer workbox.
I also agree with Brian, no matter what, make sure whatever you purchase is truck packable. To add to that, try to purchase the correct number of cases to make your chosen dimension usable. Such as, if you choose 30" trunks, buying only 2 of them doesn't make sense. You'll have to buy 3 if don't have anything else that's already 30". If you only need 2 trunks, go with 45" wide. If you need 4 trunks, or you want them smaller, 22.5" wide also works. FWIW, I'm currently working on Microwedge carts which I think are going to end up as 18" wide. Two wedges per cart gives me 10 wedges in one row across the truck.
Oh and if you're using vans instead of box trucks, most vans are about 2/3 of a box truck. You could do 2 30" items across, 3 22.5" across, etc..