MCRT, Forgive me if I am reading too much into your post but it may be worth checking on whether you can book a flight more than 1 year out. Perhaps the way to go is with open segments (cities without dates) but it is not clear to me as to how the current reservation systems would handle itineraries that extend beyond the airline schedules which are currently loaded. Planning a 10, 11 or 12 month long trip must have its own unique challenges!
In any case, there will undoubtedly be schedule changes after you begin a long trip so just remember to periodically check in with the carriers that you are confirmed with.