I could be wrong, but I don't think that the Storm scout is designed to have a fan in that area. There is a front-mounted fan on the bottom front, another on the rear top, and space for two on the side panel. With all those fans properly set, you should have more than enough airflow coming through the case.
You *might* be able to stuff one in there if you take out all the face plates that cover the drive slots, but unless you have some very clever roping technique in mind I don't think you will be able to get it to stay in place once the blades start moving.
Is there a reason you feel that the airflow isn't enough with the provided fan mounts? I have a SS myself and I've recommended them to everyone I know because of the excellent airflow.