Tavina Yenifer

Hiya, I want to make a birthday gift for my husband. He has a helicopter and now he needs a RC. I know that he needs Specrtum one. He doesn't want DX6. But I am not sure what to buy. Dx8 or Dx7s? Could you help me? I found: 1.Spektrum DX8 Transmitter Only - Mode 2 - £205 2.Spektrum DX7s 7Ch DSMX Tx Mode 2 - £130 3.Spektrum DX7s 7 Ch with AR8000 TX and RX Mode 2 - £170 What do I need to buy? Does he need a Receiver which is included in option 3? Please advise me as I do know nothing about this(((