I don't have any suggestions about software, so I'm eagerly following this thread.
I do want to suggest that a polarizing filter is a great thing to have when you are outdoors in plenty of light at WDW. The "blue sky and puffy white cloud" effects aren't easily "created" in photo editing software.
The downside is that it does cut down on the available light, affecting your exposure choices. Not an issue outside in broad daylight, but can be a pain if you are continually going from outside to inside and need to take it off, put it on all the time.