Guys build COROPLAST combat planes a lot here, so it just seemed like the most logical medium and in the end, pretty flexible, cost effective reusable and ultimately UPS/FedEx box smashing gorilla resistant. It comes in a dozen different colors to boot.

Purchased at local hardware store:
2- 4' x 8' sheets 6 mil "coroplast"
6 - 8' lengths of 1"x1" anodized aluminum L-angle stock
2 - 8' lengths of 1" flat anodized aluminum stock
2 - 50 ct. boxes of 3/16" x 3/8" to 1/2" grip aluminum pop rivets
1 - 50 ct. box of 3/16" x 1/16" to 1/8" grip aluminum pop rivets
3 - 50 ct. boxes of 3/16" aluminum back-up plates (like a washer but sized for pop rivets)
8 Stanley decorative cabinet corners
10 1-1/2" x 3/8" lag screws

Total cost for the parts was around $120 bucks or so...should be a lot cheaper at Home Depot on the mainland of course.
Other stuff on hand or to buy: Good quality pop rivet gun, drill, 3/16" drill bit, 1 roller cutter with extra blades....not necessary but works really good on coro., enough pieces of scrap 1" exterior/marine grade plywood to make 10-12 2"x2" squares, lots of any kind of packing foam or bubble wrap, etc.

I considered many different designs including hinged and clam shell before choosing a simple top over bottom screwed together design. Since coro here comes in max 4x8 sheets and I wanted to make all joints folded vs. spliced for strength, I made my box 1'x2'x6', but you can easily go as big as the dimension of the coro if you choose to and just use the aluminum angle to connect edges of the box without compromising much, if any strength. If you're in doubt, get some cheaper, thinner coro or even cardboard and practice the design first, before tackling the thicker, more expensive stuff. Coro is very easy to use once you get the hang of it and it's very durable.

My F-22 was shipped using the coro-cradles in the pics, and the F-5 was shipped nose-off with 4" ****r-pedic foam pads lining top and bottom with some styro on the sides and in-betweens (box weighed 90-95 pounds each shipment with transmitter, charger, small tool case, etc. packed in perimeter). Zero damage to box or contents (a frikkin FedEx miracle!) on either of 2 shipments to/from Florida from Hawaii via FedEx Second Day Air and the box should last for many, many more such shipments. I'm sure it would cost you extra if taking along on airlines, but at least it would be with you when you get to the show/home.

PM me if you'd like more info or pics. Aloha, Woody.