First, you should go into edit mode and create 1 new material ID for the model. Now you have 2 different material IDs. Go back to mat ID 1. Now select the polygons of the face and click the assign button in order to assign the material ID to those faces.
Then select the body polygons (you could hit ´´inverse´´ button to just inverse the selection) change the material ID to the other material ID you´ve just created and assign it to the selected faces.
Now you will be able to select the face by material id. Deselect all. Go back to mat ID 1and hit select. The face polygons will be selected. Now enter the Uv Selection mode. You´ll notice that the face polygons are selected here too. Hit the U key and unwrap it as you like.
Go back to edit mode, deselect all, and select material ID 2 and repeat the procedure for mapping these other faces.
The final result will be that you will see the face and the body polygons overlapped, but that won´t matter because they are using different material IDs, therefore they will be using different materials and textures.
thanks for your reply/tutorial ! I will look into it as soon as i get home from work. Really think it will improve my texturing alot to have UV seperate instead of one big map with
all mesh unwrap init.