The Orthodox would just be Eastern Catholic, and use the Divine Liturgy of St Chrysostom or Basil on most Sundays. The EO and the EC both already do this. There are other Liturgies as well, but I don’t see their exclusion when reunification happens.
Episcopalians and Methodists go the way of the Anglican Ordinariate. There probably should be a Lutheran ordinariate, but what would you call it?
Trinitarian Pentecostals would be most at home in the Syro-Malabar tradition.
Baptists and Presbyterians don’t need an ordinariate. Just let them split and split and split so that eventually they, for a lack of churches, will either have to go to Mass or stay home. Church spilts are financial timebombs.