Ask one person about bamboo, and they will tell you that Japanese bamboo is the best.  Ask another and they will tell you that Chinese bamboo is superior.  Ask another, and they will tell you that the heat of Taiwan makes for superior bamoo.  The same story will be heard for any equipment you wish to purchase.  Each supplier of kendo equipment gets their gear from a different source.  Each of these sources will have its good points and bad points.  The important thing is to ask many questions, get several opinions, and try the different items for yourself.  Since the equipment most often used and replaced in kendo is the shinai, that is the area I will concentrate on the most.  From time to time you can expect reviews of other equipment as well.