If you are switching ALL the radio stuff, yeah, I'd suggest getting a Hitec Laser 4 with the two micro servos, for 114.99 from Tower. Or at least a 3 channel....... If you are just switching the Rx, then the little crystal with the tag will have your channel. Get another Rx, and use the same crystal number (channel) to use the same Tx.
You'll be happier if you get them both flying at once though!

Jetts