If you have any kind of a spin fixture with the capability to load a blank in it, you can grind your own. I've done this with a 5C collet fixture and use the shank from an old worn out tool like an endmill or a burr.
Grind a cone shaped end. Then grind a spade type end by grinding halfway through until you get to the centerline. This will create a tool with zero clearance which may work in wood, I don't know.
To create clearance, you'd need to decenter the tool a little bit when you grind the cone. If you've got an accurate collet fixture, you can offset it by slipping a piece of .002 shimstock in one side. Grind the cone, this time it will be eccentric. You'd need to mark the direction of the eccentricity, so that when you grind the spade face, you grind it in such a manner as to get the maximum eccentricity on whichever side of the spade you intend to lead in rotation. This creates cutting clearance for the tip. Such a tool will also cut a .004 wide flat in the bottom. But because it is actually cutting instead of mushing the material out of the way, it may live longer.