Lights that ignore position.z of GameObject

Hello everyone!

I'm creating a 2D game. I've set an Orthographic Camera. The game uses meshes (not sprites) to render GameObjects. This GameObjects are ordered by position.z in order to not overlap. I've set an Spotlight, and Point light

If I raise this beautiful blob "transform.position.z -= 2f" above the ground, it is close to the light source, so this happens.

Is there any kind of light that ignore the z position of the object? I know that Directional lights don't take into account the position of the object, but I don't have the same control as in Spotlights (all the Scene is lit). Is this possible with custom Shaders?

On the other hand, is there any option of sorting layers for MeshRenderers, as in SpriteRenderer? This may solve this problem too.

Thank you!