Mirroring only potato/woody but not sid?

["Tibor D." <linux_ch@scientist.com>]

Hi folks,
I have enough of mirroring every day the whole Debian-tree (i386 only 
and without sources, with some sophisticated rsync-scripts). Is there a 
way to mirror only potato and woody? There are just too many updates a 
day for my slow 64k link, and most of them are for sid only. I think 
apt-move is not the solution, since there you first install the Packages 
(that could be slow when installing a new X), and then move the 
installed packages to the local mirror. I want the packages first in the 
local mirror, and install them afterwards (with high-speed =:)). Any ideas?
Greetings, Tibor