Two very friendly breeds you're considering! I've only ever had and interacted with buffs before, though I desperately want a faverolle.
I think both would create fairy friendly chicks and either are good option. Is there any particular size you'd prefer? Orpingtons are bigger chickens and would produce larger chicks. Faverolles are (arguably) more pleasant in coloring. So either is good for temperament, appearance is the next question.
I had 2 Orpington roos and a Dominique roo who free ranged in my vegetable garden and back yard. They got along great and the only problem I had with them was pecking my tomatoes. They loved it when I tilled up the soil.