The Debian site is http://www.debian.org/, not .net. I suggest downloading the Etch" version, a good compromise between the stable but old version and the bleeding edge.

I don't know about Gentoo. There are many Linux distros and I prefer not to get into arguments about which is "Better". But Knoppix is based on Debian, so if you wanted an Installed Knoppix then the logical place to start would seem to be Debian.