Displaying a map in the editor window

Hello All,

So Here is my question: Assuming that in a given editor window, I want to display something like a world map. Perhaps I want to have a way to interact with for example an RPG world, but that's beside the point. This world map is split up into selectable regions (this way I can select a region, and click a button to have something happen to the region). this region can be a complex path or a uniform grid.

I am asking 1) how to get a map image rendered in the editor view mode and 2) create selectable regions (think of the green selectable regions when defining a mecanim avatar) that when selected, can be used in future processing, such as when the user clicks a button to create a new event in that region of the world.

I imagine that the map rendering is trivial, as there is the drawpreviewimage of the editor gui class, but overlaying it with selectable regions is the tough part. I dont know if there is an extensible way to add onto the map rendering the way I have it described. I am also sure that the selectable region has to be some sort of special editor class that provides its name, a boolean for if it has been selected or not, and contains a reference to it that can be used when needed for further processing.

Any input on the matter would be much appreciated. Thanks