If you really want panorama's, there's free software which does a really good job
Hugin - Panorama photo stitcher
I have a few lake pictures and such posted on here built using that, it's easy to use and it's pretty good merging quality. The resolution of the panoramas is better than the ones I've seen pulled out of the sony's mainly because sony scales down the images significantly (at least on the cameras I played with) where as the software will merge the full resolution images if you want.
Most of the art filters are also available in post-processing applications and do just as good if not a better job than in-camera ones too.
If you're trying to decide what to buy, my personal advice, is to focus on the camera itself and use just your computer to do the after effects.