The traditional approach to this sort of thing in Linux distributions is to release the stuff/code in whatever form you feel most comfortable (though tarballs would be good), and let someone else worry about the packaging. It would help to have some clarity on the licensing of the new levels; anything that's a modified version of an original level is probably not going to be distributable, but anything that's original probably would be. It would make the position of potential packagers easier if you could slap a suitable licence statement on them, preferably using a well-know Free software licence. That way any packages could just pick up the licence from the level files themselves.