I've been flying my S800 in the Pelican 0340 Cube case for awhile now and am very happy with it. You can pick it up new on ebay for $200 with foam and it meets the major airline baggage size limits. The wheels are quick release so you just roll it to the ticket counter and pop off the wheels. You need to slide out the long landing skids to fit it into the bottom, but that's the only disassembly you have to do. I elected to use bubble wrap and cut foam pieces to secure the Zenmuse with camera mount. I also added the optional mesh lid organizer, which works very nicely to pack tools, lipo meter, spare parts, etc.
Of course, if I wasn't a cheap bastard I would buy a custom case or use a bigger Pelican and just pay the oversize baggage fees. But I can take two of these for free on Southwest, which flies pretty much everywhere I need to go here in the US, so this works well for me.