I'd go with carbon steel. Are you able to heat treat it? I've never tried this but I'd be curious how well it worked. Take some hard steel, such as a circular saw blade, and heat in a charcoal grill. Rig up a blower to keep air blowing through to make it hot and leave it in there until bright red (or as hot as you can) and then let the fire die down and go out over the course of a few hours. Take out the blade and cut it to shape with a hacksaw. Sharpen the edges. Now, rebuild your fire and get it cherry red. Grab it with tongs and drop it in a bucket of water. Now, I'm sure some blacksmith types are tearing out hair, but if so let me know a better color and quench media. The blade may be relatively brittle, but may hold an edge well. There are probably resources online for this sort of heat treatment. Look for steel tempering.