What is best the Firewall, Antispam, AV and other Antimalware Software

Hello All,

I need to find the best security and antimalware software for both my distro, CentOS 5.3 and my intended uses for my two VPS' and dedi. Some background about what I'm doing so you'll be able to help me better determine my security needs and the best antimalware software for my needs.

I'm trying to create the best security environment, internal and external, for my two Lenny VPS' and single dedi, which are all installed with CentOS 5.3 and a DirectAdmin CP. Before I begin loading them with data, packages, virtual OSes, etc. My intention is to install VMware server to run a virtual (KDE) desktop from my dedi to my Windows Vista 64 box, as well as a AsteriskNow VoIP and a Windows Vista 32 virtual desktop to run legacy programs that won't run on Vista 64 but will on Vista 32.

I'll also immediately begin hosting three websites, two with downloadable materials and two or three blogs, at least one with streaming video. Later this year, I intend to begin writing and selling downloadable secure ebooks from a site. I will also use the dedi to try virtual appliances of various types.

Moreover, one VPS will be slave/mirror to the dedi, as well as running its own mail and DNS server and doing primary, secure backup for business data (which will be synced to the dedi). My goal is to avoid major data loss and extended periods of downtown like I've experienced for most of this year.

In fact, I'll run DNS (for which I'm trying to install PowerDNS and Poweradmin and create a Round-Robin setup between the master and slave) and mail servers (including webmail) for on all three and file servers on at least two. I will be attempting to create secure data back up for my personal data on the third VPS. So, like I said, security on my servers is mission-critical since I know the cost of data loss a bit too intimately.

I'm looking for the best firewall, AV, anti-spam, etc., preferably secure, mature open-source packages) to protect my dedi from external threats and my VPS' from internal and external theats.

I'm looking forward to your solutions-oriented responses.

Sasha

P.S. Please don't be surprised if you see similar posts in requests for other information on other parts of the forum.