I can't think of many shoes that are preppier than smoking slippers, and the most luxurious come from Stubbs and Wootton. They are all out of my price range at the moment, with the slippers in the $400 range, but I imagine they are just so comfortable. They all have great embroidery on the front so you can a pair that fits your interests and personality.
They have also paired up with J.Crew this season to make a pair exclusively for all prep's favorite store!
I think these shoes would just be ideal for traveling! I imagine having these babies on my feet would make the airport experience that much more comfortable: