I'm hoping to redeem Alaska miles for a trip to Johannesburg in early 2012, most likely on Delta. I'll have enough miles for Business Elite.

Does anyone have any suggestions as to how far in advance to make the booking? Will my itinerary include First Class seating from my homebase airport (SEA) to either JFK or ATL to then fly to Africa?

My other option is Air France, who I love and have flown in their Biz class a few times before, so I want to experience a Delta long-haul flight in Business for the first time.

Thanks for any information.