I thought I had it already but couldn't find it in applications (I bought Anime Studio Pro by mistake). So I invested yet another $80 in software to get Manga Studio 5. This was going to be my summer holiday project but I got a bit excited and jumped the gun.
I've posted this drawing here before but I made some changes in Manga Studio today - more shading and applying a texture to the board. Easy as - just select the area with the Magic Wand and drag the texture in. Which is cool if you want to apply the 'halftone' dots you see in comics. The background is an MS freebie. I am planning to do an original eventually. And I haven't finished the soles of the shoes - you can see the clouds through them.
You can import as a psd (with all layers preserved) - which supports my method of hand drawing and Live Tracing in Illustrator to colour in another program. The pencil is much better than PS and the brushes are really nice to use. You can rotate your work easily but I haven't figured out how to do that yet. The interface is a bit different to Illustrator and Photoshop, but similar enough so you can feel your way around until you get to some tutorials. For some reason it saves automatically as RGB which is a bit of a nuisance if you are doing stuff for print but it's easily fixed.
I think this is definitely the program for people who like drawing.