Having gone thru the re-propping process on a non standard boat here are some links you may find of use.
http://www.moyermarine.com/forums/showthread.php?t=6148
http://www.moyermarine.com/forums/fo...c&daysprune=-1
http://www.moyermarine.com/forums/showthread.php?t=6046
Be aware of the disclaimer in my first post on this thread about faulty tach numbers.
Short version is that a 14 X 9 three blade proved to be a good match for my boat. 12000 # displacement, 25' water line, 2 to 1 reduction gear with proper clearances in the aperture.
Welcome to the forum.
Dan S/V Marian Claire
Edit: You may also need to address the issue that caused the zinc and prop to be degraded.