The Philips Dreamstation is a good unit that is also easy to travel with, going by the photo of the Resmed unit that Sleeprider posted the Dreamstation would be about 1/3 less again in cubic space in its carry bag [can't do a photo until I get home later today, sorry]
Make sure your CPAP goes with you as carry on luggage.
If you don't need to use the humidifier the Dreamstation splits in half and can be used without the humidifier, thus cutting the machine size in half... you could then pack it in a smaller bag along with the power supply, hose and mask.
I hope it all goes well for getting your pilot licence reinstated.. it took me five and a half months of specialists, medical tests, and sleep trials, and $6,000 AU before my professional driving licence was reinstated.
I fell asleep after my fourth long day of work and crashed my bus.. fortunately a very low speed accident with no passengers on board, and no physical injuries to me or my volunteer on the bus [worked in aged care/community transport]
It was an automatic trip to hospital for me, and an instant 6 month mandatory driving suspension, or until medically cleared by the cardio/neuro/respiratory specialists.
My situation could have been worse if loaded with passengers... I'm sure the last thing you need is to fall out of the sky because you "fell asleep at the wheel".
Keep us informed with how you get on with it all.