Secure my Rackspace Server (Harden the OS)

I am new to rackspace and I am looking for someone who can secure my server by doing the following: Setup useraccount,disable root access. Configure firewall/iptables Close ports except for those that must be open (mysql, port 80 etc) restrict access to a single IP Disable SSH keys Recommendations from you for the following: To avoid DOS attacks do you recommend installing Nagios, fail2ban, and perhaps even Snort IDS on the servers to keep hackers out. Basically I need an expert that can LOCK this box down. We will need CENTOS insalled. I have a rackspace account already setup and ready to go. I then want a detailed step by step tutorial so that in the event I need to do this again in the future I can follow your guide and do it myself. Possible Future Project: I also would like a separate quote from you down the road to setup a load balancing server as well as disaster recovery server. And configure backups. I know Rackspace has allot of this built in but I would like an expert to configure them and recommend the best possible scenarios for each. Don't worry about providing a bid on these items yet. Lets get the secure server in place and then we can discuss these items. I am also considering having someone install plesk or cpanel as well.