If you’re in the mood for something not trip hop but with a similar vocal style you might enjoy Lamb - later stuff is probably most similar, earlier stuff is a bit more esoteric.
Morcheeba, definitely. Start with "Who can you trust?" and make your way through the discography. It evolves in style, but I think you'll find a few you'll like.
This list and massive attack pretty much covers what I would call close proximity (that I'm aware of). Of course there's a myriad of trip hop sub genres more or less close to this subset, but it can veer off quite far.