Hi,
I hope you get them good homes very soon. It is a hard decision for you to have to make but I can understand why you can't take them with you. Having flown three boys only to Zurich and have them go through alot of stress I have often questioned whether I brought them here for me or would it have been kinder to let them stay in the UK.
Chapelhouse Persian Rescue & Web Shop is a very good rescue as they carefully vet the homes for the cats and have a strict adoption policy. I hope it works out for you over there. Maybe eventually you will be able to get a kitten of your own out there once you are settled in your new home.
Izzie