If you use Unix/Linux/Cygwin you can do the task in miliseconds with the following bash script.
#!/bin/sh
for f in `ls *.php`
do
(echo '/<?php/r header.txt'; echo 'wq') | ed $f;
done
header.txt is the file that lists your above comments.
http://www.nhatban.net/info/a0021.html