Honestly, they really haven't talked about Steven's immortality enough, There's really no way that it could work out with him and Connie. She's gonna die, He's going to live (presumably) forever.
I've always liked the idea of pairing Steven with Amethyst, they have a great dynamic with a lot of development and chemistry.
I think Lapis could go with Lars, lapidot is a meme at this point. Both of them have a lot in common. They both have a lot of emotional issues that they're starting to overcome because of Steven, they might be able to bond over choices they've made, plus, Lars is immortal now.
IDK about Pearl, Bismuth, and Peridot. They sort of teased bismidot in reunited, but who knows.
Or just fuck it, have 'em all be poly.
One big fuck pile