All of these packages are in the repo and all they take is a yum install. They are not mandatory packages for the PBX to function so I am not keen on bloating the ISO with these besides maybe unzip.
I must agree with Tony on keeping packages that might not be used by most people out of the standard disteo install. It is very easy to install what you need to customize the system afterwards.
I have a list of commands in a file that I paste into the system to install and customize the system after the distro is installed. For example