On Sat, 5 Apr 2008 00:10:35 -0700 (PDT), Jay
wrote:

So it's just between the two motors---the DF4 or the DF6? Anyone had
experience with either or both of those two specific motors and can
offer some insight as to the better of the two for our very limited
purpose? Thanx.

4 hp should be plenty unless you want to get on plane. That would
require 10 to 15 hp depending on number and weight of people.