Here's a link to an example of making a stool into a sculpting stand...
http://www.wetcanvas.com/forums/show...culpting+stand
and here's a link to a stool that would work well for a stand but someone said it wasn't available in the U.S. Maybe it could be found, though, with a little research...
http://www.wetcanvas.com/forums/show...culpting+stand