Check here This is the home of slap-get. Or here for more info on the types of sources.Not sure about Slax but under Debian, you have experimental, testing and unstable. Is it the case the Slax?
Have a look at this thread.I will do some googling on this, but I decided to open a thread for other users and if we end up with a good "sources" file, we can post it here.
Slapt-get FAQ
Slapt-get Readme



