I'm on a virtual host, so adding memory is a monthly cost, not a one-time cost. As I said before, Debian doesn't seem to keep up with the virus signature updates very well anyways. For the past year that I've been running my server, first on Ubuntu, now on Debian, most of the time I get the warning in ISPConfig's server monitor that the virus defs are out of date. Our client-side anti-virus gives us more protection, so why use 1/5 of the memory on my server for an anti-virus?
That being said, I used the exact procedure that I described in the first post.