If you want it to look like a painting, an action or filter won't do it. Has to be done by hand. It's easier with a tablet, but it can be done by mouse. It is, however, very tedious. Basically, you open up the photo or collage or whatever, and you treat it like a paint by numbers thing. You click on foreground color then click on an area of color in the photo, and paint just that area that color. You then pick another area, and do this with every shade of color in the image. As far as blending the colors together where different shades mix, you can use the blur tool or, more effectively, the smudge tool, but you have to be very tender using the smudge tool, It's easy to get carried away.

Yes, Painter is better than Photoshop for painting. I use both plus photopaint. But I know mnany folks who use onlly photoshop to paint.

Talent is God's gift to you. Using it is your gift to God.