I have one of this adjustable height stool, bought from Ikea perhaps two years ago. But now I can't find it anymore in their 2006 catalog. I did think about using it as a sculpting stand, but finally I didn't as I find this stool too low for this purpose.
As a sculpting stand, I often make use of a two-wheel kitchen trolley also by Ikea. On top I put a lazy susan. If one does not do knocking and banging on things on top, it should be strong enough for 100 lb and perhaps 150 lb works. For small artworks, I put a sitting stool on top and next a small lazy susan. I have more details on this including photos in another thread