The new noise reduction in PS CC's Smart Sharpen dialogue has some heuristics that make it suited to cleaning up "pushed" skies in landscapes with little effect on more detailed parts of the image. I sometimes use Imageonics "Noiseware" plug in for Photoshop and find it does a fine job, although its many controls require some familiarity and study. Mostly, I try to arrive at the stitching stage of my panoramas with the images cleaned up as much as possible in Lightroom, which has the best noise reduction of any raw converter I have used, and which can also be used to process flattened Photoshop files.
Topaz "InFocus" can add relatively subtle sharpening with less haloing than Smart Sharpen. But there are limits. "Blur Radius" should be kept under 0.90 if you want to avoid strange artifacts. Its "Sharpness" and "Sharpness Radius" controls can be taken pretty far with very little halo.
Topaz "Detail3" doesn't actually sharpen, but emphasizes the image in a way that usually creates a sense of, uh, plenty of detail. Use sparingly, it easily goes over the top. Very effective at pepping up clouds and similar amorphous objects, but keep them on their own masked layer.
