You want to plot a 3D scalar field f(x,y,z) against all three spatial coordinates. I am not sure what you're precisely willing to do: which surfaces are you talking about ? You may want to plot iso-density surfaces, which allow for clear visualization of the field. I don't know the Matplotlib formulation for this, but with Mayavi2 (a great 3D-plotting Python library) you can use "contour3d" : http://docs.enthought.com/mayavi/mayavi/auto/mlab_helper_functions.html#mayavi.mlab.contour3d
Anyway if you're willing to do advanced 3D stuff Mayavi is way better than Matplotlib. See the gallery for examples : http://docs.enthought.com/mayavi/mayavi/auto/examples.html
Hope that helps !