The most native solution for MAC OSX, would be rsync.
Second option would be sync folder apps, plenty free and plenty $.
Just google for terms such as “mac rsync automator”.
To do it over the internet, doing it over SSH would be an option.
Here are some examples:
http://www.maclife.com/article/howtos/using_rsync_keep_your_files_sync_0
http://www.bananica.com/Geek-Stuff/Synchronize-two-folders-on-a-Mac-with-Automator-and-Rsync/
