I've traveled extensively with everything from orchestras and bands to small ensembles, and the best advice I've received is to rent or buy as beat-up a road case as you can find (88-key keyboard cases usually fit) and take it to an upholsterer to fit the foam to your instrument.
This took me about thirty seconds to find (I'm not connected in any way with it, just as an example):
http://tinyurl.com/oslba4v If you want to sell it afterward, make sure the foam is removable. Hot tip: always list the INSIDE measurement on road cases, to drastically increase your chances of selling it. I've done this a bunch of times, and nobody ever seems to consider that.
Stencil table legs or something equally innocuous on the case and invite the neighbor's kids over to beat the hell out of it. The more trashed and uninteresting you can make it, the less likely it is to be stolen (not counting table leg theft rings, of course.)
After the journey, you can sell the case. Lighter fluid removes paint from ABS just dandy, but be careful not to breathe it, and use gloves. Lighter fluid = naphtha = benzene, the most carcinogenic substance known to man.
Ship it via DHS or FedEx, because they track it over every inch of its journey, unlike airlines.