Get the computer radio. There are so many things that you can do with it. As for the Servos, If the Radio you are going to buy is the Futaba 6EXA, you will get S3004 Ball Bearing servos. So buy another S3004 and all your servos will match.
Or, buy a cheapo servo for the extra an use it on the throttle. Two hook up to aileron servos with 4 channel you needa Y connector. To do it with the computer radio, you just put one aileron in channel one and one in channel 6 and turn on Flaperon mixing. You can also turn on a 2 -> 6 (Ele -> flap) mix for really tight loops.