If you need iPhoto version 9.4.7, which was included in the OSX Mavericks GM release, here's the download link:
Do not install if you're not running OSX Mavericks!
There's no version check during installation, so attempting to install on an unsupported OSX version will break iPhoto.
If needed, you can use the iPhoto Library Upgrader to downgrade your library of iPhoto to an earlier version. In the tool, choose Rebuild library to do this. Do note that some of the features introduced in later versions of iPhoto will be erased from the library.