Use any gps you like to interface with frsky telemetry. GPS Protocol and baudrate is detected automatically. Use an arduino Mini or Nano.
In config.h choose protocol:
For D-Series telemetry choose
#define FRSKY_D
For X-Series telemetry choose
#define FRSKY_X
You can change the update rate of the transmitted data with
#define TELEMETRY_HZ 3
This will change the update rate of GPS data. The higher the value the faster the transmission and the more accurate the position. D-Series a max of 3hz is recommended. On X-Series 5hz should work well.
Connect D9 to telemetry pin of your receiver.