I think he wants to know what telemetry is good for helicopters and what brands should he be looking at. I would have said something earlier but I don't have this feature as of yet. I can say that hi-tech has a decent setup, basing on 2 brothers hobbies or 2bfly.com review. They put together almost 3 hours of video that goes through almost all of their equipment.
Now there is others out there that are just as good if not maybe better. Again I don't have this feature so I can't say honestly.