I was not thinking about a motor for my pedicab, but just a personal bike.
A major draw back in having a motor for my pedicab is that I travel quite frequently and different municipalities have varying regulation. For example local taxi codes often will refer to a taxi as either "A Vehicle...", or "A Motorized Vehicle...". This can be a major deal breaker at events. Additionally I have yet to find a motorized pedicab (not scooter) that will constantly out run me. On a personal bike on the other hand....
Additionally can you think of a solution that is able to pull 800+ pounds for 6+ hours at a time? At some events I come close to 100 miles.