I made mine from a large piece of aluminium. As usual the Tak one looks great but I guess it wouldn't be cheap. Maybe the Aust importer knows if not ask the guys at
www.takahashiamerica.com
I am guessing the pole diameter would be in the order of 100mm - 110mm. Mine is 114 but of course is custom made so not really relevant to this thread.
PM me if you need more info.