Not sure what radio you are looking at. Standard 4 channel RC radios come with transmitter, receiver, 4 servos, battery packs, crystals and a wall charger. Most trainers only need 4 servos as well. A single servo controls both ailerons at the same time. Some hgher performance sport planes have a seperate servo for each aileron. If you need more servos, you don't have to buy the same brand if you don't want to. You can buy Hitec brand servos for instance that will work with Futaba or Airtronics. You can also get Futaba or Aitronics compatible recievers ot one that works with both types called a universal receiver. Receivers are usually 7 or 8 channels. If you use 4 channels, just plug the servos in to slots 1,2,3 and 4. [8D]