There are over 75 Debian mirrors world-wide and over 7300 packages available for unstable which you can browse at http://www.debian.org/Packages/unstable/allpackages.html. Check for a mirror near you by trying http://ftp.au.debian.org/where you replace au with your country code. The following are likely to exist:
deb http://ftp.au.debian.org/debian potato main contrib non-free deb http://ftp.au.debian.org/debian-non-US potato/non-US main contrib non-free
(If you are familiar with Debian slink or earlier, you will notice that the format of the non-US entry changed starting with potato.)
Finally, if you want to go the ``commercial'' (and sometimes less hassle) CD-ROM distribution path a nice looking one based on Debian is Libranet.