Trend Micro is one of the first, if no the first, to create antispyware for free open source Linux OS (Operating System).....
Links and information to the available softwares for anitvirus and antispyware are here:
Linux OS for older Windows Machines
http://www.bluecollarpc.net/linux-ducks.html
Although your observations about Linux security neccessary softwares are at least acknowledged - the truth is that currently in the cyber criminal underground there has been a major shift to use Linux to commit "bot-herder" control of malware botnets involving up to or more than a million computers. Research "botnets" or slang: 'zombie networks'.
webmaster www.bluecollarpc.net and .org
NO TROLLS / FLAMES: for my links...
EXCERPT: Yahoo! Answers Community Guidelines
http://answers.yahoo.com/info/community_guidelines.php
"...If you have years of experience in something, have a special hobby, own your own business, or if you are a knowledge partner, it's OK to accompany a good, on-topic answer with a link to your website, blog, or email to offer more information. "