So, the problems are: flat bottom, poor maneuverability, rough ride. One company has solved all these problems:
Here's a beautiful deep-vee jet drive. Twin Yanmar diesel engines, jetstick control, so no handling problems 35 knots top speed. Draws 22 inches.
I would love this jet boat. There is a Hinckley at MVYC; beautiful lines.
http://www.yachtworld.com/boats/2018...3#.WQIITfkrJII
No price listed, but I saw several used Hinckleys for less that $500K. One 22 year old for less than $200K.