Honestly, my factory pads have lasted so long I'm quite tempted to buy OEM when the time comes.
As for rotors, I've always bought the el-cheapo Chinese rotors at the local parts stores so I can't be much help on those. I rarely replace rotors anyway - they don't seem too wear rapidly for me. But I never turn them down.
For calipers, I buy the OEMs from the dealer.
Ryan