Enhance a photograph using photoshop or equivalent

Hi, we are looking for a photograph to be creatively edited. The photo is of the River Clyde in Glasgow and as is usual in this area it is quite grey and cloudy! We don't want to over edit the image but keep it quite natural looking. I'm open to suggestions.

We are having 4 panoramic images printed on to canvas box frames and want them to all be impressive. The theme we have been going for is cityscape, lively, morning / day time.

Hopefully someone has the skills to make a good job of this.

Regards

Andrew