One of the leaders in the mobile pizza trailer business is firewithin.com. They recently updated their site with beautiful photography, an updated catalog and other offerings.
While other mobile pizza trailer companies simply build the ovens, firewithin.com also provides support with classes on running a wood fired catering business and a business manual. Workshops are scheduled throughout the year with one coming right up in June. If you are thinking of going mobile, this is one company well worth investigating.
Bill has been trying to make the perfect pizza for over 4 decades. He's still working on it.