mod_fastcgi is gone. That's now fcgid.
mod_proxy_fcgi is not dead. It's too new for centos 6 though.
It needs apache 2.4 and centos has lower (2.2?) I think. Thus you'd need to build apache yourself or find packages in rpm forge or something as it requires apache 2.4 and this module for proxy to fcgi.
You can see the module doesn't exist for 2.2 here: http://httpd.apache.org/docs/2.2/mod/ But does for 2.4: http://httpd.apache.org/docs/2.4/mod/
To summarise, what you want to do will need apache 2.4. Or just use the old school php-cgi and mod_fcgid.
Other option is nginx and fastcgi_pass. Benefit here is you can use unix socket if php-fpm is local to drop the TCP overhead
Thanks, Jason! I've been using php-cgi, mod_fcgid and suexec combo for years on my servers. Now I want to run php apps in UserDir with user credentials. This probably can be achieved with mod_fcgid and suexec but it seems like I'd need separate fcgi configs and cgi wrappers under suexec docroot for each user. If you know of a simpler way please share your experience.