That lead is toxic is a valid point. If you 'loose' some into your carpet, or where-ever, it is something that can harm you, your pets and your children. When you dispose of it, it is gonna be hard to get rid of (toxic, remember)
So I agree with all the alternatives as being just as good. (Especially if you ever intend to move them! Weighing 250lbs each is harder to move a few feet or even a few inches! than 60/100lbs of sand or whatever.