I think that would work better with Inkscape or Illustrator. You could do it in Photoshop with some layer-styles though. A tip on the regions: for each region, create a layer as a colored mass on that layer (1 layer for each region). Then set the layer transparency to something like 70% and add in a "stroke" layer style a few pixels wide of the same or a complementary color.
Hey Thanks,
You Helped me out Allot just by saying those few things
An when he gets to heaven
To Saint peter he will tell
"One more marine Reporting sir...
I have served my time in hell"