Narrowed down plotlines

I have narrowed down my ideas to Idea 1 and Idea 3, so to make up my mind about my final concept, I want to piece together some potential information about characters, clothing, props, storyline, titles and locations. As both of my trailer ideas are under the branch of z-ombie thrillers, they will have a dark theme and concept, therefore they will not be one for the light-hearted.