Congratulations on the purchase. That is one of my all time favorite hulls. X2 on the pictures.
Have you driven the boat already? Do you have any data on various speeds and at what RPM? To really nail an impeller cut, that info is required.
Just to make sure I understand your specific needs before making a recommendation, please let me know if I missed your point.
The way I understand it is that your primary goal is economy at cruise speed with top speed and hole shot a distant secondary concern.
Normally, what we would recommend for hulls like yours would be a B cut. That is the best compromise between acceleration and top speed. It's small enough that it will allow the engine to reach the RPM at which it makes peak power, yet big enough that it still provides a good hole shot.
As GT, my esteemed colleague, pointed out, cruise economy of jet boats is less than stellar. With that being said, what I would do to maximize cruise economy is go with an aluminium AA or maybe an A+ impeller. A larger impeller can always be cut down if you need more RPM.
As far as the brand impeller, American Turbine is top quality or get a Heritage from Place Diverter. Both offer service parts.
All of this assumes proper clearances. Regardless of which impeller, a properly detailed impeller will make it "bite" harder and ultimately work more efficient. A detailed bowl will also help the pump work more efficiently. Less cavitation translates into more thrust.
Some other suggestions to optimize your boat. I would pass on an inducer. I would ditch the rock grate for a loader. If a shoe and ride plate are in the (off-season) budget, I would suggest a back-cut shoe with a 13.5" opening and the biting edge ~1/16" above keel. A Place Diverter will help you optimize your trim.
Good luck,
Joe
