How are you flying with your pit equipment?

We are packing our pit equipment, and I need a good way to stow it on the plane. We are taking 5 or so boxes of tools and parts. We already have our robot transport figured out.

How are other people taking their pit equipment?

I want something that is strong enough for what is being carried, meets the size requirements, and is painless for TSA to inspect.
We have some heavy duty plastic totes that can be locked shut with TSA locks. They are really strong and good to carry, but may be too large.
We can put our boxes in a suitcase, which would be about the right size, easy to open/inspect, and can be rolled around. However, with all of our heavy stuff inside, I am not sure if the frame and fabric outside can handle everything.
The most appealing option I have thought of is a big sports duffel bag. They are designed to hold big bulky sports equipment. They are really spacious so I can consolidate some other equipment we are taking (like a tripod) to save on checked bags. The walls strong yet flexible and forgiving.

What are you guys bringing? That could make a difference.

Currently, my team is stuffing all our stuff into the remaining area in our suitcases.