Thanks for the replies.
Yep, the dogs are Siberians, the bitches are small-ish, none, bigger than 40 lbs, most of my males are between 50 and 55, depending on condition and I have 2 "donkeys" who weigh 65 each.
I have IATA approved varikennels for each dog, these are stackable.
Dog paperwork is all in order, Pet Passports held and we know what the US require to enter.