you need a radio where both transmitter and receivers are fast and exact. I'd recommend the Sanwa brand. as for the number of channels, no, you're not going to need 3 channels for EP on-road racing. but the functions that are the most important (expo for all servo curves, subtrim, servo speed, EPAs for all servos) in a radio are available on radios that have at least 3 channels. so just ignore the number of channels and focus on features.