RE: Pulse XT40 prop size
Even that this size of prop. is recommended on the manual, I would go for a 11 x 6 prop. and 15% or 10% nitro fuel with a mix of synthetic and castor oil.
A 12 x 6 will provide a better responsive model at lower speeds (A good amount of mass of air trough the control surfaces) but I personally think that is asking a lot for this great engine.
Congratulations for your new engine and model and let me know how it works.