Jay, it sound to like your getting real serious about this performance thing. The race layup that you have on that hull should really fly with NOS.
As far as your skeg goes, if you havent done one before you should not do it yourself without looking at a lot of modified skegs and then deciding what you want done. If I were you with the kind of power your going to have on tap in that lightweight boat. I would send the case to someone like Titus, JCs, or Bobs. That boat may be capable of over 120 if the case is done right. If you had a car that would go that fast you would want to run a set of recaps on it. (Do they still recap tires for cars) Well you know what I mean.