I would recommend Bryan if you can get it. You won't have to climb the hill if you stay there. If thats not an option, I would try for the Shively, Perkins, Bush, area (stick to East Green). The walk would be short in any of these. I lived in substance free for 2 of my 4 years at OU...That just means that alcohol and tobacco use are not tolerated (kicked out of the building if you're caught). Some dorms allow alcohol in rooms if the residents are 21, which is not the case in substance free. Also, the environment tends to be a little calmer than most other dorms.