Get thee to the nearest thrift shop and buy a floor lamp.  Ideally, one of those 90's torchieres --they are easy to work with.  All of them have a heavy cast iron base under the decorative cover.  Now you take out the electrical stuff and throw it away, and call someone who likes to solve mechanical problems--maybe yourself?  My duct tape form has a plywood bottom, and I found a pipe flange at Lowe's that would slip over the stem of the lamp.  I screwed the flange to the plywood, held the form up to myself, with the lamp alongside, to get the height.  You will need a friend to mark the lamp stem for you.  Cut it with a hacksaw, slip it into the flange, done.  I placed my form on a flat TV turntable and adjusted for the added height.  Theoretically, the form should be able to rotate at the flange-pipe junction, if the flange is just the right fit and is long enough to give a really stable junction.  Mine didn't, so I use the turntable.  It leans ever so slightly because the junction isn't perfect, but for my purposes, it works fine.  Maybe someone out there has a better way, but for a few bucks, you can't beat a floor lamp for a base.  Hope this helps.