I wood build a wooden box, only safe way.. and you can use it fourever..
Got a real RC head a few months back, they ripped us on priority shipping..70 or 80 bux.. double wrapped cardboard, padded.. shoulda been OK except, it took WEEKS to arrive, and they dropped it, and broke/dented a pair of the intake spigots.. already ported thin ones.. fun times fixing them (rooling eyes).
Anyway after former ebay experiences, I will tell you, pack it in wood, make sure it can handle a 3ft drop.. or you will probably be dissapointed.. having a box for heads and cylinders, just makes good sense when hauling the stuff around...jmo..