If you get small fonts in Debian build, just run:
apt-get install xfonts-75dpi-transcoded xfonts-100dpi-transcoded
and then restart your X server.
Hint: Instead of restarting your X server, it seems to be sufficient to only restart the X font server (you can keep your X session running):
/etc/init.d/xfs restart (as root)
This has been tested on Debian Sarge. You might also install the package xfonts-base-transcoded. To easily set the font (and theme), you can use the package gtk-theme-switch. You might want to a quick read at the skins article.