I sometimes scan my watercolor images and print them, and the only way
they create the values and definition in the original image is to print
them on a inkjet specialized coated paper.
Yup, ink-jet on watercolor paper creates an 'ink-jet on watercolor' look.
The good or bad of it is up to the printer: sometimes it works, sometimes
it doesn't. Profound, n'est ce pas?
Weren't the first 'giclee' prints - early 90's - done on watercolor?
attempts to create a watercolor look with Photoshop ... really
[don't] make it
Have you tried 'Fractal Design Painter'? I used to play around with
it, never quite got the hang of using a pen tablet instead of a brush.
I think it does great at 'water-color-type-things'; great fun to play with.