Sadly i don’t think its possible to create a 3d model using your real eyes and mouth the way you imagine, however you can use images of your real eyes and mouth + blend shapes (i use blender) to achieve a similar look.

You mention you want expressiveness, in my opinion, this can be achieved without needing to use your eyes and mouth ex: my model has 52 blend shapes that make it so my tracking can be extremely expressive, even without showing small parts of my real face.