You might want to go overkill on the cooling side too - 2 fans?
keep the motor temperatures down.
Don't forget tuning rotors too - they might give you that little edge you're looking for.
Look at the whole picture, not just what is giving out the power - reduce weight as much as possible.
In your situation, I would be tempted to get a Tekin redline gen 2, and a tuning rotor.
I race on foams too, but 13.5 blinky.
Have you tried Modeltech for getting the motor? They stock Corally