Ok, I've replaced the first image with the intermediate version, less contrast but still that deep and dramatic atmosphere
paquito: Well, very simple to combine the images, I render one image with HDR, one with Sunlight and I simply use Gimp with one image per layer and playing with the alpha slider to let the background image overlaping the foreground one until the result is what I expect, I also use the eraser to increase the transparency in some parts. Nothing special as you may guess.
gabrielefx:Yep, displacement would be really welcome