Macs are highly customisable – there’s a lot you can do to make them look and behave the way you want.
Snapz Pro is superb for screenshots.
Westciv’s Stylemaster is excellent for writing CSS. They have a new version in beta and it brings some extremely user-friendly advances.
For FTP I’m a great fan of Interarchy.
I can’t comment on Quickbooks or genealogy software but you can find listings of Mac software in many places including VersionTracker at http://www.versiontracker.com
Do remember that at the moment Macs don’t suffer from spyware or viruses (though Word and Excel have some cross-platform viruses).