Apparently United Cutlery is produceing the official set of kunai throwers with some nice spec's. 12" overall made from aus-6 and what looks like an half decent sheath.
http://www.unitedcutlery.com/ProductDetail.aspx?itemno=UC2772&cat=NW
click the button under the pic that says download spec sheet and you'll get a better pic plus all the info in a nice pdf file.
http://www.unitedcutlery.com/ProductDetail.aspx?itemno=UC2772&cat=NW
click the button under the pic that says download spec sheet and you'll get a better pic plus all the info in a nice pdf file.