Aquariums: Getting closer, stocking ideas?

I will be adding some more plants, botanicals, micro fauna in the near future. It’s a 37g tank, I’d say between 15-20 gallons of water. Since I feel I’m close I need stocking ideas! I was considering wild type bettas, ideally a mouth brooder, maybe two or three pairs depending on how plants fill in. Or a group of Pygmy Everglades sunfish and some least killifish. I’m open to suggestions on what y’all have kept and what would be fun in this type of set up! Thanks