Where are de 16 " x 7 cougar mags?
Factory fitment for a 2000 SW Ford Cougar V6 2.5i is a 215/55R16 which fits the factory 16x6 wheel as stated on the tire placard and in the factory manual.
All the sizes you list here will put the speedometer out by ~5km/h at 100km/h.
...not sure on what’s the best / biggest / widest / maximum tires or rims will fit your car?
Write about the tires you are currently driving on.