That motor is gonna be overkill, but I'm sure you can tame it down a bit. I wouldn't go out and get another motor. As far as what to get, it's a little tough to do without narrowing things down a bit. For example, what's your budget?

For a radio, I run a DX3R Pro. But the DX3R or DX3S or DX2S would work fine too.

For a steering servo, I've had good luck with Associated's XP 1015 servo.

For racing, you're only allowed to run 4 cell max. And 4S with that 2250 motor is plenty fast for speed runs. You wanna get something with at least 35C and 5000mah. That means the battery will supply about 175 amps, which should be sufficient for 1/8 buggy racing.