11x7 doesn't get the 46 FX in its power band. What brand prop? Try APC 11x6 and rev at 13k+.

This plane at 6 lb. is a little heavy for a 40 size aerobat. You don't really want the extra 8 oz of the 61 FX. Instead, look into bored out engines that weigh the same as 40's, such as the Magnum 53, OS 50, Irvine 53,... I think Magnum 53 is the best value and most powerful of these.

Saito 120? Vibration and torque on this little plane is not worth the extra power, not to mention weight. It's good to overpower to some extent, but not to the point when you have to increase the weight by more than 10%, do major mod just to make it fit, and worry about prop ground clearance.