atabites and/or other speaker fillers

Lead shot is the way to go to fill up speaker stands. No worries about magnetic properties. Given the rate that magnetic force diminishes with distance, I doubt that there would a significant interaction between a speaker and it's stand. An exact calculation of the forces would be complex.

Lead shot on the other hand has an issue of a lead dust that is extreamly dangerous...

What about monitor speaker stands that can be made of low-carbon steel that is very vulnerable to magnetizm?

Mark,

While lead is indeed a dangerous material to ingest I believe that lead shot is perfectly safe. A gazillion hunters have been using lead shot and continue to do so without any harm to themselves whatsoever. There have been studies done on people that reload their own sheels in quantities you couldn't relate to. Lead poisoning is not an issue unless one wants to make it political. Remember, lead is only outlawed in waterfowl hunting. Most states still allow the use of lead shot for upland game birds and I believe nearly all trap and skeet shooters use lead shot exclusively. Your fears are somewhat over the top on this one.

Patrick