RE: Quique Somenzini YAK-54S 73"
Hitec and Futaba connectors are interchangeable. I dont think the JR connector will fit without some forcing.
It's best to use heavy duty wires if you are using high torque servos or long runs. I think they classify anything larger than or equal to 20 gauge as heavy duty. (remember the smaller, the number the bigger the wire dia)
Dave