I'm building a 3rd garage bay on my house and I'm hoping for a little guidance.  This bay will be isolated from the other two that are used for daily drivers.  I'm planning to have a 12 foot ceiling and a  
lift. 
  
It will mostly serve as storage for a concours restored Chevelle  

, so I'm mostly concerned with flash rust on natural parts.  There will be a vapor barrier under the slab.  I'm also planning to insulate it and have a small space heater for the occasional winter project.  Any suggestions on how I should construct it with minimal moisture issues?
Thanks, Mark