I'm holding a Niten Ichi Ryu bokuto at this moment and would estimate that it is under 1 pound in weight, it is considerably lighter than a standard bokken
I bought mine from Nine Circles www.ninecircles.co.uk/
they will ship internationally.
Having used this bokken to suppliment Aikido, Kendo and Iaido applications it has stood up to the same hard knocks given to the 'fatter' bokken normally used. Only down side is that you can't use tsuba with them.