video and radio transmitter for the plane, which will require an FCC license
.60 cubic inch to .90 cubic inch powered R/C plane minimum with servos and radio gear
video reciever and radio reciever for ground control(PC)
lots of time and ingenuity and some experimentation
A couple thousand bucks, maybe more
if you want it to fly automatically you will need to write some software and also probably add GPS to the plane and to the PC as well
sensors for the plane--altimeter and airspeed minimum connected to the radio system so you can get the telemmetry---may be able to piggyback that onto the video signal by muxing it in with it like audio data would be