xBee's don't have a great reputation for being reliable in the world of hobby quadcopters, so I'd be scared of having a runaway robot unless I did some testing first.
I have had great experiences with R/C products from FlySky. This hobbyking radio with receiver is a rebranded ct6b radio from FlySky. I've gotten over 100 yards with mine.
http://www.hobbyking.com/hobbyking/s...Mode_2_.htm l
You'd need to use interrupts to get information from the receiver though. I have code that uses pin change interrupts on an arduino that can read the receiver that I can send if you want.