You don't always need to change your rotors. Have someone measure them with a micrometer and if they in spec, just get pads and wear sensors.
For the rear rotors, if you do change them, make sure you adjust the parking brake shoes afterward.
If you don't mind the oem brake dust, just stick with oem. I went with hawk hps pads and centric rotors on the rear of my car. They dust way less than my front does.
Got the rotors and pads from tirerack.com
Turner and tischer are great vendors too.