How about buying one in Korea? I'm pretty sure you should be able to pick one up there, as long as you aren't going to the North that is.

I took my snowboard once on the plane, and countless guitars. They have vertical compartments like closets that will fit the KC.
I would worry more about those ass at security check.

Either keys is okay. I bought my Korg Extreme from Singapore last year and there wasn't any problem. The only rule probably is that you have to check it in depending on the airline. I would advice you to buy an ATA flight case for your Indi or KB.