At the end of the day, the point is to diminsh the possibility that these tall, skinny setups tip over as much as possible. Weight in the base or lower part of the configuration is probably the most effective way to accomplish that, short of screwing the stands into the floor.

The cat, the dog, the rambunctious toddler - this is a defense against the evil knocker-downers. If you can garner something aesthetic in the mix - so much the better. BTW, lead shot can be purchased at any gun store.