Howtoforge posted a tutorial about setting up a server with ISPConfig 2 and CentOS x86_64

This tutorial shows how to set up a CentOS 6.0 server (x86_64) that offers all services needed by ISPs and web hosters: Apache web server (SSL-capable), Postfix mail server with SMTP-AUTH and TLS, BIND DNS server, Proftpd FTP server, MySQL server, Dovecot POP3/IMAP, Quota, Firewall, etc. In the end you should have a system that works reliably and where ISPConfig runs out of the box.

  The Perfect Server - CentOS 6.0 x86_64 (ISPConfig 2)