I second that. Ubuntu has easy codec install. You go to the upper panel click System > Adminstration > Software Sources. Then check em all. Make sure their all checked in the Ubuntu Software tab, and in Other Software. Then open a terminal and type :

Sudo apt-get update

You should be good to go. You see, CentOS is just a recompiled RedHat. I'm not sure why CentOS is a must, but if your comfortable with it, It should work. You may have to configure it a bit, but it's a good stable system. An excellent server platform.