The approach is a team-question. Take someone who is perfect in setting up a scene, another person who is a magician on shaders. Get somebody who will do the atmospheres - and last not least, get a couple of people for setting up the lighting.
I doubt that a single sun with GI will do within reasonable rendertimes. You'll need fill-lights, spots etc. -TU is on a very good way. But he'll need some help.
My 5 cents,
Volker