.htaccess - htaccess UTF-8 encoding for .html, .css, .js - Whats the best way?

For yslow page speed I want to remove my meta tag and put my encoding into the .htaccess file. Below are all the ways to do it I have read about. Which is the preferred way? Also is the language setting a good idea too - and if out side of the filesmatch will it apply to all file types?

1) https://github.com/jancbeck/My-Wordpress-Boilerplate/blob/master/htaccess.txt

AddDefaultCharset utf-8
AddCharset utf-8 .html .css .js
DefaultLanguage en-US

vs

2) http://www.askapache.com/htaccess/using-http-headers-with-htaccess.html

AddDefaultCharset UTF-8
DefaultLanguage en-US

vs

3) I suspect this is all that's needed. But untested.

AddCharset UTF-8 .html .css .js
DefaultLanguage en-US