Since you're really looking for changes to the normal map, not the shader itself, I would recommend using whatever existing shader you'd like for the overall color/material properties, and then you can use a tool like this to convert a 2D grayscale image you make in Photoshop into a more precise normal map:
We used to do a lot of dimple textures on our products, so this was a much quicker way of executing those. Just keep in mind Keyshot doesn't have the best UV mapping tools, so you may with weird corners or surface intersections. The only way around that is to properly UV map your object in a real rendering tool like Maya/Blender/3DSMax and then spit it back out into Keyshot with the UV's saved.
If you aren't familiar with UV maps, you can find a lot of resources for unwrapping online. It tends to be harder with really high poly models you might be generating in CAD, but there are tricks depending on how detailed you need to get.