I would like to know if there would be a way to bundle together seperate
pieces of sotware to match the equivalent of Astaro Linux ?

It seems like it should be a way to do it yourself, but I don't know where to start.
Here's what Astaro brings to the table:

Web Security
Spyware Protection blocks incoming spyware, adware and other malicious applications, and prevents them from sending out confidential information.
Virus Protection for the Web defends computers against virus infections from web downloads and web- based email.
Content Filtering can block Internet access to 60 categories of web sites during working hours.

Email Security
Virus Protection for Email catches viruses in SMTP and POP3 emails and attachments, even in compressed and archived formats.
Spam Protection uses eight different techniques to filter out spam without stopping legitimate emails. Phishing Protection blocks emails from criminals trying to trick users into revealing confidential information.

Network Security
Intrusion Protection detects and blocks probes and application-based attacks using heuristics, anomaly detection, and pattern-based techniques.
Firewall, with stateful packet inspection and application-level proxies, guards Internet communications traffic in and out of the organization.
Virtual Private Network assures secure communications with remote offices and “road warriors”.

I would love to hear alternative solutions to having to buy the Astaro Linux Product (it's like X number of dollars for X number of IPs) -- I'm not sure (would love to find out) but I believe they are using open-source software (be it commercial or not) and they are simply bundling this themselves along with the hardware if needed.

Any ideas on possible software so one could come up with their own list to make their own all-in-one security solution?

Thanks in advance!