You could probably style them in your stylesheet.css.

You'd have to create specific id's for them

#languages { ]
h3#languagesHeading {}
#languagesContent {}

Add the styling you want.

You may still have to work with the language files as well as the sideboxes files making some modifications.

Check these two articles from the turtorials.

http://www.zen-cart.com/tutorials/index.php?article=135

http://www.zen-cart.com/tutorials/index.php?article=134

These may not be exactly what you want but they give you a jumping off point.