It looks like the real problem is reliably "harvesting" php scripts from other sites in their pre-parsed state.
the simplest way I can think of is to setup an alias without PHP interpretation and use httpd authentication.
Alias /server_root /php_off
<location /php_off>
AuthType Basic
AuthName Somename
AuthUserFile Yourhtpasswdfile
require valid-user
php_admin_flag engine off
</location>
Just setup a single username / password pair with htpasswd
Now you can fopen with http://name:password@server.com/php_off/file_i_want_here.php