multibyte/multilingual support

We have a CMS which is written is based on php & mysql. Recently we received
a request to support multiple languages so that sites in that particular
laguage can be created. I did some search on the google and it seems I have
to build in multibyte support for php and mysql. Mbstring
(http://us3.php.net/mbstring) claims to support multiple languages with a
caution saying it might not work properly.

After further research it seems unicode might be the way to go, since
unicode can represents all characters (in all languages) with integers,
which in turn can be handled in php as it has excellent integer support. But
again since all the data is store in mysql we need unicode support for mysql
too and it has 2 formats (http://www.mysql.com/doc/en/Charset-Unicode.html)
usc-2 (for storing data) and utf-8 (for encoding). Finally, we decide to
stick with utf-8 as it could support more languages than usc-2 and also
since php has utf-8 support.

Our application evolved over time and it was not very long ago that we
introduced a new DB layer. Even though efforts were made to change code to
use this new DB layer, I am afraid there still might be instances where we
use the php mysql functions to access db. We use egexes heavily and do a lot
of text manipulation, so that rules out any chance of being closer to utf-8.
So I am wondering if there are any good approaches to this issue i.e. modify
the existing application code minimally to handle utf-8 (that doesn't sound
right!) and make it all transparent to the presentation layer. Any
suggestions or comments are welcome.

Turi
http://aijalon.net