Hi
I have done this for a few boats. Probably the best of the lot would be a Graupner Electro Vee. Can still be had used sometimes on ebay.
They just got lucky on the hull bottom design. The boat can perform great at much higher speeds than what you would get with the original power. A good 700 and 12 good cells and you got a 30mph+ boat that can take the turns and hi seas.
n.h.schmidt