There are no options available, as they did expire a while back without any having been exercised. At this point it is almost certain that no additional Viewliners will be ordered or built. Will you please just let it go and move onto something more useful?
The difference between CAF and NS is primarily that CAF's Viewliner shell did not fail the buff strength test miserably. Notwithstanding that I believe CAF has lost money on the Viewliner deal hand over fist, and probably does not want to hear the word Viewliner again, once they are done with finally pushing out the last Sleeper almost a decade late.