a) you can find flights that allow you to keep your pet with you and yes most vets will give you something to calm to pets nerves down.
b) its not a good idea to let them put your pet with the cargo, there are non stop horror stories.
here is a list of airlines that allow pets with you
http://www.petflight.com/airlines/carry-on
These guys
http://petairways.com/ will take your pet on a plane, they have handlers on board etc then you meet your pet at the destination, its another option