1. Where can I find a pair of Aviadiors online? (Preferably in black)
  2. Try eBay - they have been discontinued here in Australia for over a year - I don't know if you will find them retail in the US. But they seem to pop up for a reasonable price on eBay stores and privately.

    I have them in the tortoise brown and another in black - they are my faves.

    Good luck!