Well that stuff all depends on your budget. High end, you can go with a competition Brushless/ ESC combo with a spekturm receiver, high speed digital servo and a 4200 LiPo. Or you can buy a cheap brushed motor, sport ESC, 27mhz receiver and a $9 servo that runs on a cheap 1800 NiMH. Normaly, people build their cars up to the high-end point. I would suggest starting with a simple ESC and motor. Then get some good NiMH batteries.
I've ran on a 27mhz receiver for the longest time, and had little problems. Mostly because people changed to the spekturm 2.4GHz receivers, so that left a lot of the other channels open. I've made the change only a few days ago.
Tamiya 416X/ Tamiya TA-05 IFS/ Losi XXX-SCT/ HPI Baja 5SC/ Tamiya M05/ Tamiya F103/ Tamiya F104/ Team Associated 10R5O/ Kyosho IGT2/