Brandy, congratulations on your new babies! How long will they be traveling to get home? If only a few hours I wouldn't worry about them having to potty. If over six hours or there is a layover they may feel the urge, but by far the majority of kittens I've sent or received have never soiled their carrier, including the one I imported from Germany that took 20 hours to get here.
As for the carrier, if you are going to carry on, any airline approved carrry-on carrier is adequate as long as it meets the size requirements to fit under the seat in front of you. If shipping in cargo, any carrier that is airline approved for shipping can be used. I have flown across country with kittens under the seat and although I know some prefer to ship cargo for long distances (and I do for an intact male) I personally feel that shipping cargo is more stressful on the kittens as it is noisy and isolated, although this is probably just my bias because I think wherever they are they will most likely just curl up and sleep for the majority of the trip.
As for the carrier, if you are going to carry on, any airline approved carrry-on carrier is adequate as long as it meets the size requirements to fit under the seat in front of you. If shipping in cargo, any carrier that is airline approved for shipping can be used. I have flown across country with kittens under the seat and although I know some prefer to ship cargo for long distances (and I do for an intact male) I personally feel that shipping cargo is more stressful on the kittens as it is noisy and isolated, although this is probably just my bias because I think wherever they are they will most likely just curl up and sleep for the majority of the trip.
