I'd hang your helmet up w/ the rest of your welding PPE w/ a cover, since when (not if) you get another welder (TIG, stick) your needs will change. Also, unless you have no friends who like to hang out at the shop, you'll want a simple hand-held helmet so they can watch and kibitz while you fix their stuff

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Extra wire, tips/extra cup maybe, MIG pliers, anti-spatter/stick spray, wire brush, cylinder cap seem like good stuff to plan for in the cabinet.
You can probably pick up a used desk side file cabinet w/ different size drawers for not too much green or even free, and some rear wheels from a junked mower (lots of those around) and a couple of caster, and you're off.