I've made a complex model, what would be a nightmare to texture in gimp. So I'm asking you, if there is an option to paint in Blender itself, watching my 3D creation? It would be a lot easier and faster that way. If you need the model, just ask for it. Oh, and I've added armature to it. Will the texture follow the body while it is deformed?
I think you can use a Texture Paint mode and paint the textures using a Stencil option.
Enter the Texture Paint mode and set up the shading type to Texture. Add a new texture in the panel on the left, then go to the Texture header on the right, select Brush and open a texture, which will be used as a stencil for painting.
Enable a Stencil option in a panel on the left. Press:
-LMB to paint through the stencil
-RMB to move it
-Shift+RMB to make the stencil bigger and smaller