The requirements for traveling in the cabin are pretty much standard. Your pet must be able to stand up and turn around in the carrier. We estimate 11-12 pounds the maximum weight for domestic flights usually.

If you fly out of Orlando, you should contact Delta or United. They both have only one short layover. The airlines will transfer your pets as long as they remain on the same airline. The flights are under 5 hours. Your pets will travel asmchecked baggage in the hold which is pressurized and temperature controlled like the cabin. You will need IATA compliant pet crates like those shown here: http://www.pettravelstore.com/categories/Pet-Crates-%26-Accessories/Pet-Crates.

You only other option is driving. We know of no trains or buses that will allow pets that will get you where you need to go. I cannot advise you on which way to travel except to say that the airlines transport thousands of pets each year with few incidents. You are the best judge of what is best for your pets.
Susan