The OP's knives are pretty decent. I have a friend who made a pretty sweet bigknife/machete with recently.. Basically he had some 1/4" steel, some bizarre grade used in bridge building competitions, ground that into a blade with tang, heat treated it, then cast a handle around it out of aluminum after drilling a couple holes in the tang. It weighs at least 6 pounds.
You could use the same method of construction to make these, just add a plastic coating to the handle. PlastiDip might even work if you could thin it down somehow.
..If you used this method, you'd have a blade that would hold an edge, and otherwise be almost exactly like the Halo ones. Couldn't take it to a con, though, better stick to painted wood for that.