I got mine from CarQuest. I ordered them from RockAuto but they were sold out! Napa also had some but the same brand from CarQuest was like $10 cheaper each.

 

I had ordered some napa premium rotors but the weren't packaged good and came damaged. They told me those were the last rotors they had for our car (in the state anyways). I ended up finding some OEM Mazda rotors on Ebay that were being sold by Atkins Rotary. $50.00 a piece. I bought all 4 they had on the auction. I figure one day these will be all dried up so I'd have some spares. They were packaged great from Atkins and arrived in perfect condition. I'm very happy.