Gleff thanks a lot. I'm sorry if this is the wrong forum but as I said I'm new to this. I have nearly 200K points in Amex Rewards so that looks to be the best choice.
But I have over 600K on UA. I wonder if I can transfer UA miles to Delta? Then I suppose I could either book the trip directly with Delta or perhaps transfer the miles to my AF account. FWIW I have a Delta Gold card which might help I guess.