Well I've found these and they will do the job, but I was hoping to find something a little more attractive or beefier.
The house has concrete floors, and with the 4X6s the bed will be heavy but no more so than a traditional 4 poster and certainly less than any waterbed. Difference will be that our bed will NOT creak, wobble, flex, or shimmy...
Pretty much regardless of what is going on...
Besides, in the event of earthquake, we'll have a safe place to hide.