fosters and smith does dog carriers and lots of other pet supplies. Probably want a soft sided cage to put under your seat (unless you think it might be going into cargo in which case, you must have a hard sided carrier).

Vets today say never to tranquilize your pets while flying. It depresses their breathing which is not something you want on a plane. If you have a pet that's prone to getting excited, then benadryl is ok, but you should test it out in advance to see how your pet reacts (it can potentially make some more hyper).

I'll be feeding all my monsters benadryl when we fly to Italy. I'm hopeful that Yoda can go under our seat so only the boys are stuck in cargo.