I use Blender for modeling (unless I create a Vroid model). In that case I use Blender to manipulate the mesh of the model (i.e. my Dorka avatar). I add or fix bones in Blender as well. I then use Unity for animations like eye blinks. Paintstorm Studio (or other paint software) is used for textures. I save them to the model in Unity until I am ok with how it all looks.
In case of the Avali, I found a blank, publicly available model without bones or texture..
I don't have a shop but I am on DeviantArt, I also make some of my Vroid models for Synth Riders, a VR rhythm game. Nothing is sold, it's just a hobby of mine and sometimes I think I spend too much time on this.
I also do portraits of RL people :)