Some good info in this thread. Like others have said, there really is no reason to retrofit an existing setup unless you want telemetry. While I was putting together a Carf Hawk, I purchased an 18MZ and even though I was initially going to use a 6014 RX in it, I knew I would eventually switch it out so I could get telemetry so I used three sbus mini servos for gear and brakes(two gear valves to have scale gear doors on the Hawk/T-45). They were used as normal servos with the 6014 and then hooked up to the serial bus when I switched out the RX. All flight surfaces were put on the PWM outputs of the 7008. I should also mention I'm using a SmartFly power expander pro in this setup. Since the SmartFly regulates logic power to the Rx to 5V/1 amp max, I tapped the servo power bus off the SmartFly and fed it to the sbus servos since they couldn't be directly hooked up to the SmarFly. The nice thing about the sbus servos is being able to program many different variables like dead band which is helpful especially for controlling air valves.

Marty