If you are buying containers for storing your goods, CSC certification is not needed. However, you have to ensure that the containers are still vandal proof and jemmy proof. Padlocks can be used for additional security to secure the lockable handles fitted to the four locking bars.
Depending on your storage requirements, you might need additional fittings like shelves. You might also desire to have light fittings inside. It is best to have these done by the container sellers, who are familiar with container specifics.