something like cPanel's Easy Apache, ie. a GUI for recompiling Apache and PHP. That means having a backed up set of compile flags for the user's last build of Apache and php. A suggested set of defaults. A GUI with tick boxes or something of that kind to select flags.
Maybe some help links guiding the user through what the various options are for.
Also some way of making sure it only uses repos where all the libraries and extensions are correct versions so that compile does not bail out with a dependency error (always a fear when one has taken down a live server for 'brief'' maintenance).
An ajax shell window allowing the user to view the compile process.