If your thinking of gas..think of this 1 channel for throttle, 1 channel for choke, 1 for rudder, perhaps 2 for ailerons and 2 for elevator, perhaps one for smoke thats 8..see what I mean..channels go fast..
I have a 50cc Pitts Python...1 throttle 1 choke 1 rudder 2 elevators 2 ailerons.1 optic kill switch..that's 8..
If you were to get a 9 or 10 channel 2.4 that would be all the radio you need for years....
Do you really get enough use out of the choke from the Tx to justify it? Most folks in my IMAA club just have a manual choke and run it on the ground before the first flight until it's warm and then open it up for the pre-flight.