Hey Jason. You would have to create a customized brush with a 'rake' shape or several dots like the bristles of a brush. Then, you should go to Shape Dynamics > Angle Jitter and tick the Direction option. This will allow the angle of the brush to vary according to the direction you paint, as opposed to a "calligraphy" brush.
Anyway, you really should try using Paint Tool SAI. It's very similar to PS, only that the way of mixing colors is different, more like Painter or traditional tools.
I hope this was helpful. Anything else, don't hesistate to ask.
By the way, your drawing looks great and I'm sure it'll be awesome once painted.
This is exactly the kind of direction I was hoping to get. Really appreciate it. I'm going to try that, as well as Paint Tool SAI (I'll have to do some research, as I'm not familiar with it).
I always thought mixing colors was tricky with PS, because unlike traditional paints, I can't mix like I'm used to...a little ultramarine..a little burnt umber.....and I never use black, choosing to mix my own. I'm sure you know what I mean.