ID:1382352
 
(See the best response by Jittai.)
Problem description:

I haven't gotten to that point in the game yet, but I'd like to switch from using the 'alert' function to instead using dialogue boxes at the bottom of the screen that would show the NPC's dialogue/text, with a picture of their face in said box.

Any ideas how one could do this?

Best response
On screen objects. I would perhaps make the background-gui tied to the world and use it for everyone; define the faces to their respect NPCs, etc.

Then add all of this to the screen when the time comes.

Look into some maptext libraries/articles/snippets.