Hmm ok I'll have to look into that. I was using rigify for the models, but only because it's free with blender, I actually use Auto Rig Pro (which is amazing!) But I don't know if it's legal to sell models that use it and I also don't know if the rigs will work for everyone but if they do I'll include them in the future.
In the meantime I found this video that should hopefully be helpful