I get my pads and rotors from Parts Authority or Olympic. They can also be ordered from www.tirerack.com

 

Sorry to say this, not to offend cyras21, but the cause of warped rotors is not the parts fault, it is a direct result of how the driver uses them. If you were to modify your driving habits to avoid (as much as possible) high speed braking above 45 mph, and to avoid holding the brake peddle at a dead stop after a hard stop (keep coasting slowly to help cooling) you will find the rotors will not warp. This is very important after running some hot laps around an autocross track, you will see cars parade around the paddock area; they are cooling their rotors.
But if you really want to get the best materials, I recommend a slotted (NOT Drilled-they crack) rotor that has been cryogenic treated (heat treated) and do a proper break in proceedure which involves a few high speed hard slow downs back to back, then allow to cool slowly. I like ceramic pads for low dust, long life the slotted rotors keep the pads from grooving the rotors.
For a 2009 Chev 4wd Burb from http://www.centricparts.com/
You can find these at various auto supply sources:
<table class="Centered" id="PartIntDataGrid" style="width: 500px; border-collapse: collapse;" border="1" cellspacing="0" rules="all"><tbody><tr class="alternate" valign="top"><td align="left">Power Slot Slotted Cryo Treated Brk Rtr</td><td style="width: 150px;">126.66057CSL</td> </tr><tr valign="top"> <td align="left">Power Slot Slotted Cryo Treated Brk Rtr</td><td style="width: 150px;">126.66057CSR</td></tr></tbody></table>
Proper bedding in your brakes:
http://www.zeckhausen.com/bedding_in_brakes.htm

I am not an expert, just experienced.

 

I don't buy much from autozone. But if you drive her hard you will have problems alot faster.