Welcome to a GREAT hobby
The Spectrum radios are one of the best radios out there. One of the best features of the Spectrum's is its model memory. You only need 1 transmitter with multiple receivers to run a bunch a trucks. Really is a money saver in the long run. I would say that most people try to low ball the initial truck only to find out it really does pay to get the best you can afford or even splurge on the radio with future builds in mind. Also keep this in mind if you want to install an MFU in the truck. Much simpler to do as you build the truck than after it is built.
PLEASE do not for get some type of gear reduction unit for the truck. I doubt if I would still be messing with the trucks if I wouldn't have taken peoples advise and installed a GRU in my trucks. You go from a race truck to something that is closer to true scale speed and much easier to drive for very little money.