I avoid working with metal, for lack of tools and experience.
What metal would you use, and what cutting tools?
Well, personally, the "type" of metal (quality, etc) isn't super important, it's more about the look & feel of it. I don't know if you remember my
GoNY Club-Axe project? For the axe-head, I used a piece of low-grade steel that had previously been a blanking-panel for a server rack (a "perk" of IT work). I cut the basic shape out with an angle-grinder, & finished with a rasp & belt sander.
The blade on this tomahawk looks like a triangle with a small rectangle-hole in the center. It also looks like there is a metal section encircling the handle where the blade is attached? For that, I'd try a short length of steel pipe, slotted, so it would slide over the axe-head. Then I'd use something like 'Devcon Metal Patch & Fill', to close any gaps between the metal surfaces.
Anyway, awesome project, love that flick. :thumbsup
And FWIW, I also lack tools & experience working with metal...