I have not used black bamboo but am intrigued with your assertion of having problems finding primitive shaft material. What is wrong with wood? We have Hoop Pine and Victorian Ash/Tassie Oak they make excellent shafts, There must be others of our native species such as the Wattles that would make good shaft material, In addition if you live in areas where exotic (European, American etc) trees grow you should be able to find plenty of Poplars and Birch, Ash and Elm etc.
Craig.