By default Cpanel comes with apache only, if you need to install Nginx,Varnish to make faster service you can use several plugins, I will start with free one and then tell about shareware.
Plugin comes with already configured Nginx and Varnish, to install and use terminal
wget http://prajith.in/downloads/apachebooster.tar.gz tar -zxf apachebooster.tar.gz cd apachebooster bash install.sh or sh install.sh
after installation you will see apachebooster in WHM plugins
You can configure Varnish and Nginx from here, and also purge varnish cache if needed. I think this plugin have have all what is needed but if your searching for more you can buy Cpanel plugin from Unixy, I think they have same functions but anyway it up to you which one to choose.