RE: Tx up to 550$ for turbine jet
You are overlooking one of the best radio systems out there (in my opinion): Airtronics! The SD-10G is awesome, and you could even use the much less expensive, 8 channel Airtronics RDS-8000 for a sport jet. Both of these radios work great and are not prone to interference at all (and use the same type of freq control that Futaba uses).
I have flown all the high end JR, Futaba and Airtronics radios, and my first choice is Airtronics.
Keith