Configuration Management
There are plenty of software tools that handle configuration management for you.
http://en.wikipedia.org/wiki/Configuration_management
Configuration management can be used to maintain OS configuration
files.[11] Example systems include CFEngine, Bcfg2, Puppet, and Chef.
SSH
You have plenty of options, for example if you simply want to ssh into multiple servers and execute commands you could use something like Fabric
http://docs.fabfile.org/en/1.8/
Fabric is a Python (2.5 or higher) library and command-line tool for
streamlining the use of SSH for application deployment or systems
administration tasks.
It provides a basic suite of operations for executing local or remote
shell commands (normally or via sudo) and uploading/downloading files,
as well as auxiliary functionality such as prompting the running user
for input, or aborting execution.