Looks interesting. What about new Yamaha 70's? Had a quick look at website a didn't see any max horsepower stated. If 50 's are giving 25 - 30 Knots 70's should give that @ a lower RPM and a little more top end @ WOT for glassed out days. Most on here will want regular updates on the build process with plenty of pictures. Hope that it is everything you are looking for.
Cheers Kevin