There's a fantastic thread at the top of the forum with some details on how to choose a system.

Go with the highest voltage you can budget. I'd suggest 6s minimum for such a large hull. You will want to use a motor such as the Feigao 580 series, pick an appropriate wind to match your LiPo choice. Pick cells with minimum 25C and 5000mAh. 3/16" Flex should be a minimum.

So there's no confusion. Kv X voltage = unloaded RPM. This does not determine how fast anything will go but may determine how quickly your electronics will fail.

Ryan