Hi Crimson Cornersw:
You can find a great deal of information on Unit Mixes by going to
Inside Self-Storage and use their database search. You will find a "Search" box in the upper right hand corner of the Home Page. If you type in Unit Mix you will get ISS magazine articles from a variety of authors. This is one of the best free research services on the web for our industry. After being a part of this industry for the past 23 years, I can tell you that designing a final Unit Mix is more art than science.
Best of Luck. with your project.