Hey guys, check out Webmin, "a Web-based system administration interface":http://www.webmin.com/
I read about it in the October (sic) issue of Linux Forum. It's in Portage (app-admin/webmin) and looks like it covers a lot of the configuration requirements. In fact, looking at the screenshots, it is very comprehensive. I'm not on my home network this week and cannot merge the package to check it out, but apparently there are third-party modules as well. Basically you can add to the tool as you like. Seems a great idea and it may be that the existing Gentoo version in Portage is good enough but, if not, you could cook up some more modules.
EDIT: Webmin can be used to configure remote PCs or your own PC. To use it to configure your own PC, point your Web browser at https://localhost:10000/