Buy a Bike Friday. They are custom fit bikes if you need them or standard models if you are lucky enough to fit a standard bike. BF makes a whole range of models and prices. They are designed to fit into a suitcase and you only pay the cost of a second suitcase on some airlines. Some South West for example it is still free. The bikes are not quick fold but can be folded in under 30 minutes after you do it a couple of times. Since the custom builds are built aff you favorite bikes measurements they will ride very similar to what you ride now.
Www.bikefriday.com. Roger