1. To control servo u need PWM of period around 20ms. When u vary the duty cycle between 0.9ms to 2.5ms it turns from one end to another.
2. To use a keypad there several ways. You can use external interrupts or interrupt on change for a 4*4 or similar kind of matrix keypads.
List of components:
1. microcontroller(PIC/AVR/ or any)
2.Current driver like SL100 or even a H-Bridge can be used
3. 4*4 keypad