ArtRage has a free starter edition you can try. It is the best paint program ever. I never use my expensive Painter ever now. ArtRage has some tools I do not love... the marker doesn't work well and there is no watercolor but in every other regard it is superior to Painter in every way and the brush strokes render hugely faster and more realistic.

Cloning from photos is much better too since it doesn't lay down the matching pixels but just samples the color dynamically from the source.

I use Photoshop for watercolor style using layer methods and layer styles but for every other kind of digital painting I use ArtRage. I can not recommend this software strongly enough... once you get going with the stylus you forget you are not making a real oil painting.

The pencil is also the best out there.

The only thing I really miss from Painter or some of the ink pens and those watercolors but really ArtRage is vastly superior. I just wish I could run my old Painter 5 on my current machine for the watercolors... I think Painter 5.5 was the best version of that program. Now that ArtRage supports layer methods I should see if I can use those to obtain the watercolor effect I want.

Anyway, you should try the starter edition available from the designer at Ambient Designs since it is not hobbled or crippled, just lacking is some features like stencils etc.