Cool idea and sketch and nice start in ZBrush.
You will sculpt without symmetry all the way? Interesting.
I think you will have a few problems with the topology being so messed up in some areas, especially the arms and hands. If you have a super computer, forget my remark, you can make the whole scene from a cube if your PC can subdivide to 50 million polys.
Interesting thread, I`ll be watching this one for sure.