I'm wondering why you feel you need to send both components to the same place? Booster Dewey is hands down the best for booster restoration and Brake and Equipment Warehouse is outstanding for brake cylinder restoration.
Brake and Equipment warehouse doesn't paint the master cylinders black, so when you get it back you will need to paint it, put some protective plugs in the outlets, use Rustoleum semi gloss black to paint the entire assembly, and after waiting a week for the paint to dry, you are all set! If you want to, you can bolt the master cylinder to the booster and paint the entire unit together. But as far as finding a "one stop shop" for both components, I think you are much better off sending the booster to dewey and the MC to brake and equipment.