There are alot of them floating all over evilbay, but they are crap! They consist of a very cheap ( dangerous and brittle ) blade, that is glued into the tsuka ( handle ). Some of them have different colored ito ( cord wrapped around the tsuka ), and the tsuba ( hand guard ) comes in different colors. There are alot of inconsistencies in these katannas.
It's hard to say they are completely movie accurate, but to hang on the wall and look at, I guess you could say they work! But they are not even worth more than 30 bucks at most. Whatever you do, do not try to use them in any way!