There was an earlier thread about training khukuris a few months ago.
I am skeptical that anything made of wood or plastic will have the weight to make a realistic training implement.
My recommendation is this: Buy the cheapest piece of junk khukuri (or khukuri-like-object) that you can find. Grind or file the edge off so it has no edge at all. For extra safety attach some kind of padding around the edges. Maybe duct tape some foam or rubber in place.
You will then have a training khukuri with the same heft as the real thing, but not as lethal. It can still knock someone senseless or bruise up a training partner, but it probably won't maim or kill anyone by accident.