If you're into the vibe but not the singers, you might like And So I Watch You From Afar, Earth, Pomegranate Tiger, Plini, Polyphia, The Algorithm, Godspeed You! Black Emperor, If These Trees Could Talk, Pelican, and Polarization. All instrumental metal/rock at different levels of heavy.
That's kind of a long list but I hope you find something in it 😅
Congratulations! You'll both do incredible!