Ditto on the nylon servos; they are fine. And coreless is a waste of money for a project like this as you'll never feel the difference, but it's your money so spend it how you want to. I don't suggest overpowering a plane for the intermediate flyer. The likelihood of crashing because the plane was going too fast is much greater than the likelihood of saving it by powering out of a stall. My first stick was a .60 size and I put a .61 engine in it. It was fine except for when I wanted to do a tall hammerhead from a near stalling horizontal speed. I put a .90 in it and it will pull fast vertical for as long as I want it to. What this plane is really about is learning orientation in any and all possible maneuvers in a bird that is easy to recover from mistakes and handles the wind very well. That's what makes for a good second plane. There is a very good reason why sticks and 4 stars get suggested so much- they have the perfect combination of maneuverability and forgiveness to let a developing pilot work on his skills without worrying about one mistake costing him an airframe.