help with choosing parts for project
 

I'm looking to design and develop a remote controlled motor. The way i want
to implement is to have a RF transmitter chip which will recieve digital
inputs (pushbuttons) convert it to analog signal and the transmitter will
then transmit the signal to RF receiver chip which will then convert it back
to digital signal and send it to a PIC microcontroller (16f818, specs: 3V,
4MHz oscilator and 1 Mhz internal clock). The PIC microcontroller will then
understand the signal and increase or decrease the speed of the motor
accordingly. (Basically the concept is based on a remote control cars which
kids play with).

I'm interested in knowing which kind (specs,brand etc) of RF receiver and
transmitter chips can i use to work in this project. Obviously being a
college student i would like to purchase cheap parts :) Any input will be
higly appereciated.