Brake parts help?

I'm looking to replace front calipers, rotors, and pads on my '98 K1500 ext cab and had the following questions:

Any suggestions for OE parts? I saw Brembo rotors listed somewhere. Should I go with the "name brand" or go with something else? All seem to be about $50

Any suggestions for on-line vendors?

Should I have the new rotors turned before installation. I've heard of problems with rotors that are warped out of the box. How common is this?

Thanks
Patrick