First of all: You have bought a quality-motor! They usually run cool, and your motor could deliver 1900Watt. I love the Actro`s.

I think you should look for at least 1500 Watt for your plane, AUW could be as much as 5,5 kilo. And I would not go for 6S, look for a 8S setup, and use two 4S LiPo`s in serial connection if your charger is too small. Higher voltage and lower amperage give you a cooler setup, it is the amperage that is dangerous. (And you can use the 4S in a .40-size acrobatic)

Personally, I would have bought the 40-5 and ran it on 10S LiPo