Did you buy that yet? I have the same one for my son, he likes it, i don't( he's only 5). The trigger finger is tight, so if you have big hands, go for something else. Also the steering knob is weak, not much resistance or throw. Other then that it does work well, taken some abuse and held up fine. As for the third channel, you will need some kinda light control to plug into the third channel, and your lights will plug into that, so it'll control the lights from the changing 3rd channel.
Another option for cheap yet decent remotes is the tactic ttx300. For around 35 on Ebay you can find one from a chop shop taken off either an arma or an axial. Way better quality then the goolrc, and you can get it into program mode and adjust the endpoints on both throttle and steering. Can even change the 3rd channel for 2/3/4 position, giving you more options for future use. Also the reciever is water proof.