Unfortunately you only get specific uniforms if you are a Dispatcher or higher. There is a official uniform for Drivers however which costs 15 Robux, however this was made out of use following Version 1.0.
None of the Uniforms can be purchased except for the Drivers uniform. Some users have taken the clothing templates and reuploaded them.
Due to Charlie's inventory having been made private, you cannot see the uniforms, purchase them or download them unless you have the link or template already.