I've seen CGRetired type out the explanation that electric power systems must be chosen based on the finished plane many times, and he's always right! You get your plane ready first, then pick a power system to run it. To answer your question about your selections being right though, your motor and ESC are appropriate for each other, but your battery is way too big. It won't hurt the motor or esc to run on that battery, but the battery will be too heavy for any air frame appropriate for that motor/esc. If you go much over a pound ready to fly with your completed design (RTF means your total takeoff weight), you're going to be under powered even using the biggest prop and a 3 cell battery.