I was in the same quandry when setting up my gasser. I decided to go with a simple solid state switch from rcatsystems ( http://www.rcatsystems.com/electronics/rc100.php ). The main problem I have with killing with the choke is the ignition system is still hot, so theoritically the engine could fire if the prop is turned. With the ignition kill switch the chance of this is reduced. Also if the reciever loses power the switch is normally open so the engine will die. So at least the engine won't be running when it hits the ground.