Distributing IntelliJ inside a company

Code style should be stored with the project, this way all the developers will have the same automatically.

As for the plugins, you can either host your own repository (https://www.jetbrains.com/help/idea/2016.1/managing-enterprise-plugin-repositories.html) or put the required plugins into the plugins folder for all the users with some custom script/installer (https://intellij-support.jetbrains.com/hc/articles/206544519).

See also https://www.jetbrains.com/help/idea/2016.1/synchronizing-and-sharing-settings.html.