I don't have experience with PetAirUk, but I did what you're doing in reverse; I shipped my dog from the US to the UK. I found it relatively straightforward, and much cheaper not to use a pet transport company and to just do everything through the airline. Your pets will most likely fly as cargo, and most of the big airlines have a specialist pet shipping department. I used Virgin and would recommend them to anyone. One of my mother's friends is a breeder and ships her dogs all over the US and the world using Delta. I've also heard BA is good for pets. So it may be an idea to do a bit of research on your own and find out what you will need to get your dogs to clear customs, and then call around the airlines. All of the customer service people I spoke to with Virgin, Delta, and BA were very helpful. Continental was a bit useless. Hope everything goes well for you!