This is what we use to make Brewing Cocoa.
The machine can handle volumes as small as a table spoon to a cup or two. Stainless steel jars with Stainless steel blades dispatch of any materials that you can think of. Of course, it even has an option blender that you can use as a regular juice blender and as a general food processor. It can help make a killer mole.
The strong 650 W motor works well to grind down nibs into smaller powder that can be added directly into the melanger.