As far as speaker stands, buy anything heavy. They don't fit those speakers (perhaps with a modification they would), but I have M&Ks speaker stands for my S150s... they are like over 100lbs, no sand.... and, get this...they are made by York (the barbell company for those who haven't been in the gym lately).
But, buy heavy. Avoid sand if you can, it's a pain.
-Chad