Uploading dynamic info to a file in php

[Ares]

I am creating an intranet application in php that is running on a client's local server. I need to be able to "push" certain data from my MySQL database out to a file or list of files that need to be able to be read by his public website, hosted on a shared hosting environment.I plan on sending these files out every hour via FTP to the webhost.What type of file format would be easiest to use for this? I am used to using MySQL to access data, but have never accessed data in a flat file before. Should I use a CSV file, or I have heard of SQLITE? What would be the best way to perform this? I do not want to give the website access to the local mysql server on site since the internet connection could go down here and customers visiting the website would be without data. Also, it would not be as fast to connect the website to the local MySQL database.I would rather not create a remote MySQL database to push the updated info to, since it will only be a few pieces of data.Both the internal application and the website are built using the Codeigniter PHP framework.