Research and Planning: What do my models need to look like?

For my magazine I will need several photos firstly I need a image for the front of the magazine and I will then need several for the contents page. These will need to show my genre especially the image on the front cover so choosing my model is very important. If I am using a girl they will need dark hair or bright hair as this is what I have found from my research. If they are male the same applies however they also need long hair or almost no hair. I need to find someone who is willing to help me with this and also fits the genre.