I guess it looks like you have no choice - you and the cat will simply have to endure the flight. Just make sure he has a carrier large enough to avoid having to lie in potential accidents, and make sure the water carrier is suitable and won't run dry/spill. I'm not sure how you can check this, but would you be able to check the airline for if there will be ANYONE with access to the hold during the flight? I would imagine there must be some member of staff who goes to check animals on such a long journey.
Has he a Pet Passport, or will he be going into Quarantine? Why would you want to fly him back, if you are moving over here?
Good luck! Ems
PS. It might be a good idea to get the carrier he will travel in now, and leave it in your home for him to sleep in, to get him accustomed to it and get it smelling like him.