If youre going on a budget and do not want to spend the money on these serious servos then i'd recommend putting some Futaba 3010 in. They have very little slop, 6.8kgs of torque, nice robust gears and are the best value for money servo around. You could buy around three or four of these for the price of a JR 8511/8611. Still recommend putting a coreless or digital on your elevator and possibly rudder if youre going to 3D it hard.