Here is the selection for drivers, conductors, astronauts, and captains: 

Notes on driver, captain, astronauts, and conductor costumes by Dr. Bon: 

Drivers: Racecar drivers can wear any of the NASCAR or top speed choices.  

Boat captains: you've got choices here - be a cheeky pirate or wear a captain, fisherman, or choose a sailor costume. 

Astronauts: this one is super clear - there's a relatively large selection for these. 

Conductors: there are a couple of train engineer costumes, or wear a dark suit and grab a conductor's hat.