Take a lie-flat bed instead
Originally Posted by RRONIN
8 passengers with carry-ons and 1 large bag each, I expect. Several vintage guitars and a case (large luggage bag sized) with pedals. I'd wondered if the X+ would be large enough for a flight of this duration.
I’m a former flight instructor, now typed in the CE-525/CJ3. I’m going to give you a somewhat different opinion.
Instead of taking everything in one G450, why not take the passengers in the Citation X+, and the luggage in your Citation M2? The cost will actually be less to take the 2 Citations, and you could go along in the M2 if you want and fly a couple of legs yourself – which will be excellent Oceanic experience.
Most comfortable alternative: Even a G450 will have to make a refuelling stop en route (the Citation X+ will have to make two). So the most comfortable option would be to fly non-stop commercially to Tokyo. Business class non-stop in an ANA Dreamliner (lie-flat seat-beds) will be even more comfortable than the G450. Send the luggage in the M2 with contract ferry pilots. That way, the M2 will be available in Japan for side-trips (such as moving the luggage between islands). And you can get some international flight experience flying around in Japan.
PM me and I will send you the mission profiles for both the Citation X+ and the M2. It's doable, even with the head-winds. Cheers.