I have a wooden training katana. It was actually bought for London Anime Expo last May, but we didn't take it because of London transport issues with carrying weapons. If it had been fake, it would have been allowed, even though a "fake" bit of wood can still be used as a weapon. -_-

For the real deal? I don't know many places you could buy them. There's this old antique shop nearby a cinema/shopping centre place I go to which has sold some. Personally, I think it's an old junk shop.

Also! You can by them at the Expo. They're not all replicas of game swords either. But good luck getting them home if you didn't drive there. @_@