I think offering to "audit your server security" and then not either telling us what the audit entails or what software you'll be using doesn't make me want to rush to take up your kind offer
I was ironically looking at nessus
today to possibly run this on our work network periodically via cron to test the security of all the (heterogenous) machines we have attached (both inside and outside the hardware firewalls we have in place).
The problem is that you can test your company's network security yourself via nessus, but no-one you're trying to impress (e.g. for contract bids) will believe you and you end up having pay thousands to a third-party security testing company, who probably either just run nessus and produce a pretty report or possibly run an inferior tool to nessus.
Still, nessus is handy even then - you run it, sort out any problems, run it again, get a clean bill of health from nessus and *then* bring in the expensive external testers - they should find a pretty clean system and give you a good security rating and, just as important, they'll probably only need one run (cos you probably pay per test run) to give you that good rating.
Oh, why isn't nessus shipped with Fedora Core 2? It's a very useful security tool and is GPL'ed. I can't understand its omission at all...