Vertical thrust really depends on how your weight is distributed. No two boats are the same really, others say to start out parellel to the part of the hull you will be running on when on plane. I always give it about 1/4" towards the water to push down on the front a bit to eliminate any porpoising. Just be sure to work some flexibility into your mounts for adjustments up or down.

You didn't mention what type rudders, for easy stop sign type I used .125 because it's what I had but you could go a little lighter. You'll have to check out aerokirk or Corkys builds to see what they used for the airfoil type. I always use the stop sign type because they are much simpler with no offset on the pivot. There really isn't any noticable difference in performance or mechanical advantage with the thrust numbers we see on the minis in my opinion.