If you search the garage journal you will find everything you will ever want to know as just about everything has been covered. However, it requires leg work on your part. You won't get much traction with a "what should I do" thread as there are many guys that are dreaming so those threads get ignored. The building you posted looks awesome. My only thought was to make it look like that and not the industrial building that it actually is requires some expensive siding work that the one in the picture seems to have. My other comment is that you will need multiple access doors and the heating cost with that much space will be tremendous, even at 50 degrees. Also, can I store some cars in it when it is done .