If they are all on the same server, can you not just update the include path?
// This is to be done once:
echo dirname("../../header_sup.php");
// once you have the full path:
$path = '/place/path/here/';
set_include_path(get_include_path() . PATH_SEPARATOR . $path);
Since it will be in the path, you can just use:
include "header_sup.php";
I've yet to work on SSL Servers so I haven't experienced this issue as yet, but this would be my first attempt.