Pelican and other plastic cases are way to heavy and increase cube quickly. When we needed boxes for each person, comms and other kit to easlly palletize, we did a lot of searching (1/1). We found a box company Zarges (Swiss and US made in NC). They are strong, stackable, can have wheels and handles and were easy to make inserts for. The drawback was cost. We had to wait till we had some money. But the boxes are awesome and last longer than anything else I have seen. Here is a link.
http://www.zargescases.com/