i have the aem/niss. pads in the front with power slot rotors. i have had this for like 4 months and now it is letting off a sh*t load of dust. Why? 2nd I am thinking of doing new rear brakes and rotors. I did the front ones myself and i bet it isn't that hard to do the rear. should i get the rotors as the fronts or should i get something differant. and what pads should i get.

 

The slotted rotors are accelerating your brake wear slightly - picture each slot as a knife edge of sorts, passing over the pad material. Might explain the dusting.