Here are my steps for setting up Ampache. I used VNC for some steps; I’ve left some dirty work for you, Fourdee, in regards to doing this all in terminal.
LAMP
Grab ampache from https://github.com/ampache/ampache/archive/3.8.0.tar.gz
Extract, rename folder ampache-3.8.0 to ampache (I used VNC, of course you know how to do this in terminal)
Move (I used VNC, of course you know how to do this in terminal) ampache folder to /var/www/ (perhaps you should prompt at install if the user will be using this as a server for anything else; you can forgo the ampache subdirectory entirely if you want ampache to be at the root, which is how I have configured it. You can use rsync. If you're doing this, be sure to remove the index.html from the default apache install)
apt-get install php5-curl
chmod -R 777 /var/www/config (/var/www/ampache/config if using subdirectory)
Open /etc/php5/apache2/php.ini and make the following adjustments (I'm not sure how to do this in terminal automatically; of course you could prompt the user to do this in vim):
upload_max_filesize = 20M
post_max_size = 40M
echo -e "deb http://www.deb-multimedia.org jessie main non-free" >> /etc/apt/sources.list
/DietPi/dietpi/dietpi-apt-get_update 2
apt-get install deb-multimedia-keyring -y --force-yes
/DietPi/dietpi/dietpi-apt-get_update 2
apt-get install ffmpeg -y
service apache2 restart
From here, the user can setup ampache in a browser via Server_IP (Server_IP/ampache if using subdirectory)
During the web-based setup, the user is prompted for the MySQL Admin user/pass, so be sure to add that to the instructions if you make a thread for it.