Music for Triduum - introducing choral polyphony to the parish.

I want to know thoughts on polyphony used for English Novus Ordo Masses - thinking of using it for Maundy Thursday and the Easter Vigil.

The parish has had no official music program (until me, that is lol) and now is willing to pay about 4-6 singers to boost the untrained parish choir. I'm wondering how this would be received, if we did more complicated (ornate) polyphonic mass settings, motets etc? Or should I just stick to the 4 hymns and normal English Mass setting.

Happy to take as many tips as you guys can offer! Both myself, the singers, and the parish are new to this level of music.