Bob,
I live in the northeast and often travel to CA. I went to Anaheim to check this place out and talk to the staff. You can basically decide on any height for the shell and if you want an overhang. You just can't sleep in the overhang, but it is great for storage. At the time I was thinking about 18" over the Tacoma cab. Also you can get the rear to be both a hatch with a mandoor. This may give people options with regard to having a pull-out live in quarters in the bed and then keep the shell on and use it to haul to make money. Price is right too.
I would have done this but getting all my stuff to the west coast and then do the build was impractical, so my year one 2014 was a Class B Campervan. Year two is my Prius conversion.
Brent