At that size a Graupner 700BB 9.6v on 12v will go well with a 40mm S type prop. My Lesro Sortsman has had an MFA850 on 12v and a Graupner 700 on 12v. I'd strongly recommend the 700! This setup draws about 20 amps stationary as measured with a wattmeter and I use an Electronize 30 amp esc. I like these as there is no setup and they are the same both ways so it doesn't matter which way they are setup. They are bigger than the Mtroniks which also work well.
I have found with this sort of power you need to consider carefully the size of wire you use and the normal Tamiya connectors aren't really man enough- I havehad them fail. I use Traxxas connectors exclusively now as they are easy to solder (I found the Deans type can melt and they need a heat shrink sleeve- Traxxas dont) and they connect up nicely. Component Shop.
You can get a 700 motor with a built in fan- I run two in my Rapier and with water cooling as well the motors are very cool after a run.
I'm on the cusp of getting into LiPo batteries as I find Nimh tend to drop voltage when a lot is asked of them- my Rapier takes 33amps from the pack and the voltage drops from 12v to around 9v on full power. Lipos are much lighter for an equivalent capacity
I have looked at these Aeronaut boats and I think they look great- I have a Diva waiting in the wings but I like the look of the Queen.
These observations are based on my experience to date (limited!) and are only one man's opinion.
Good luck and do let us know how you get on.
All the best….Ian