I feel like kind of a jerk my making my first post on the forum so... critical... I'm just trying to give some advice though.

For blending the image together, you can just overlap the two halves of the image on top of each other (on separate layers) and then select both layers and go to "image/auto blend layers". It'll probably blend them perfectly, but if not, you can just move the images around a few pixels and try again. Then to get the colors, you run a quick "Image/Adjustments/Auto Colors" over both of them, and you don't even need to worry about hand touching the clouds, or clone stamping the trees.

Also, the only thing that doesn't look absolutely awesome with the final image is the water, I'd suggest copying some of the water from the original image, and putting a filter/distort/sphereize on it, and then moving it over the center of the final image...

I can't really verify that any of that would work because I don't actually have photoshop open, but theoretically it's sound advice.

Whatever way you end up doing it, be creative, have fun, mess around with stuff, enjoy. =D