For the style of photo you are going after, I would say #1 is the best. Much stronger composition and processing. The magenta tones in the sky blend into the darker overall scene in #1. In #2, the scene is much lighter in appearance, and so the magenta sky really sticks out and feels like it doesn't belong.
The first image definitely has a much stronger composition. Although the grads cast colour into the sky it does match quite well with the colour of some of the foreground rocks, in the second image however the sky feels quite unnatural and stopping down much less would have been a better choice.
The first is a tremendous shot. I love the drama. The way the foreground pebbles mimic the sky colours is really good. Makes the colour cast work a treat.
Ute
Very cool shots, Paulo. The first one works best form me. The rocks in the upper part of the photo provide very nice framing for the beuatiful colors in the sky and water.