Just for labeling, I'd go with Inkscape. It is free, and will let you do all that other jazz like text on paths and individual letter kerning. It is what I use for my labeling. Of course, it won't provide the natural media stuff you are looking for (neither does Photoshop, for that matter). This is available using a variety of different packages. One nice one that may not be around (or has changed names) is Deep Paint. Another one is called Painter (iir). Just google for natural media painting software and you should get some good options.

-Rob A>