For servos i like to run the ace/xp/ae ds1313 for throttle and ds1015 for steering. You can buy both for less than $75-80/ea brand new. Theres even deals to be had on them in the buy/sell/trade section here if you don't mind used.
The go engines imo are great, tons of power and hold a tune really well. I have never had anything else in my buggy so i can't really compare, but i've had other sized motors in other vehicles and the go engine compared to them are very impressive.