I didn’t know we could list stores or I would have.
I think since the op is a novice at avi making they should start with a shape. Since redbone can mean anything from light skinned black woman to mixed black woman there’s a lot of looks they could do. I can’t think of that many shape makers off hand, but the one that I do remember is Unified. Unified does shapes for all of the major bodies: maitreya, slink and Belleza. The only thing is her style cards don’t really tell you which skin she used, but op would have a good basis to work with and skin choice can really alter an avatar’s appearance.
As far as skins, Itgirls is definitely a good choice. There’s also The Skinnery, Insol, Pumec, Milan. There are a lot of lesser known skin makers that make good skins for a redbone.
As for bodies, I’d suggest Slink Hourglass or Belleza Freya. Those two would probably allow for what I think OP is looking for in a body type.
Theres a thousand bloggers op could look at for style. I’d suggest someone like Volupturaptor Pearl or Coco Ranks.
Its hard helping someone with their avi when you aren’t sure what they want. But OP should have a lot of choices from these suggestions.
Good luck!