That looks good and I think a sculpt tool is a great way to get what you need.

I don't know blender all that well but in my old 3D app I used to apply a black and white striped texture to the X or Y axis of the model and then you can render the 3D shape textured and all of the Z heights cut through the stripes and give striped contours from which you can do the edge detect to get thin lines. Maybe now its all done procedurally so you can set the color based on the Z height directly. Or maybe blender has a plugin to show contours. It seems to be able do everything these days.