shoot a message to Dawson - bassboy1 - ... I bet he can weld you up something that is better than you can find anywhere to buy
All you would need would be a 4"x4" square plate with a 1" square tube welded to it that extends off the front bow about 8" (so a 15" total length), then have another bracket welded to the end of that tube with a plate perpendicular to the tube so that you can attach the motor... if he sees this post, he might even have a better idea, but I'm just thinking out loud.
Here is an example of what I'm talking about - unfortunately, Seasense doesn't have these available any more, but I did see one in our local tackle shop a few weeks ago.. price was around $30, but I don't know how well they hold up.