RE: Ranges of Futaba?
Bax has it right.
The range is determined by the receiver, not the radio. With Futaba, if not stated, then it is 1 mile plus. Only the ones that Bax lists have shorter ranges.
If you want to look at receivers that will work with your Futaba radio, Hitec's receivers are a perfect match. I have a Futaba 9C and a Futaba Conquest. I use all Hitec receivers.
For a sailplane I would recommend the electron 6 or the supreme 8, depending on how many channels you need.