Photoshop is enough really, but yes, quite a few of us do work with multiple programs. For what you want to do, you might consider Corel's Painter. It offers far more options for actual painting. Programs I myself use are Photoshop. Paint Shop Pro Corel Painter Corel Photopaint CorelDraw Why do I use all those? Because each program has different strengths for different things. There are things that are easier to do in Corel PhotoPaint than in Photoshop, and vice versa. Photopaint is equal to Photoshop in most ways, but Photoshop is the standard program. The advantage is that files and images transfer easily between the programs. You also have some other choices for doing what you want to do. There's GIMP, Dogwaffle and Pixia, all of which are excellent programs on their own. GIMP and Pixia are both free programs. And if what you're looking to do is paint, rather than work with photos, GIMP, Dogwaffle or Pixia might be better suited to your purposes. I'm not familiar with GIMP or Dogwaffle really, but i know a lot of anime artists use Pixia.

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