Oh heavens, I just realized you're in FL! FIRST, contact your county health inspector. Before you buy a bus. Before you buy any equipment. Find out what you need, what you can sell and where you can set up. FL is a PITA to operate in. Go to http://www.roadfood.com
and go to the forums (scroll down to Restaurant Professionals & Professional Hot Dog Vendors... food vendors post in both forums). There are some folks there that are in FL. And a couple are in either Broward County or Palm Beach County (or both).
BTW, my 40 ft Blue Bird FE All American has 35 ft behind the drivers seat.