Re: Zipkit
I don't know that you are going to find another kit supplier. They seem pretty well focused on the sail and oar end of the spectrum, as I must admit am I so my depth of research into motorboats is limited. That is a cute little runabout though, Glen-L might have something similar in their catalog. Popular Mechanics also put out instructions for this type of craft "back in the day" they put out at least one book of their designs. You would be building from plans but that shouldn't be too much of an issue.
Steve
If you would have a good boat, be a good guy when you build her - honest, careful, patient, strong.
H.A. Calahan