Just a reminder...if you want to book airfare that far out, just do it through
ABD, once you have the ABD booked. If you book airfare through ABD, you will get your money refunded if ABD cancels the trip. In my experience, I went out and found the exact flights that I wanted and told the agent exactly what to book, down to the seat assignment. There was no difference in price. I've seen others post that sometimes the ABD agent can get an even better price (but don't count on it).
Given ABD's nebulous cancellation policy, I wouldn't even consider buying airfare on my own if traveling with them.