I have a digitrax zephyr, and I want to prchase a dt-402 walkaround throttle. Is there anythiny else I need the buy with that. How long is the cord. I also am going to buy the UR92 Duplex Radio Tranceiver. Just was wondering if anybody knows if everything I included. I hate having to wait on shipping then finding out I need somthing else. N scale code 55. THANKS.