Ambrym vs Epi vs Tongoa?

A friend and I are travelling to Vanuatu for about 10 days and wuld like to visit one or two outer islands. We are thinking of Ambrym, Epi or Tongoa becuase of relatively inexpensive transportation cost from Vila. We are keen to experience traditional Vanuatu life style and culture and do not mind basic conditions.

Which one would you recomend? Would you recommend taking a ship between Ambrym and Epi? If yes, any idea of how long it takes?

Thank you very much in advance!

Of these islands, northern Ambrym has preserved its traditional culture best.
But you still have to hit a special event to see locals in traditional (un)dress.

Thank you Laszlo!