My best information for you is to call American's Around the World Desk -- 1-800-247-3247.
The staff is great, can do all sorts of pricings and airlines for you. I have heard (and having used the desk would believe) these are some of the best agents that AA has -- including the agents at the Exec. Plat deak.
You can also set-up and itinary with them and hold it up to 7 days before your flight. Reserve now so you get your seats (as there are some capacity controls on the seats -- different inventory class) and call once a month to have it extended. We booked our honeymoon in August of 2000 and did not have to pay for the tickets until January 2001 (and then only because we had vouchers that were going to expire).
You may also want to consider 1st versus business since the RTW is so much less than the direct flights (our honeymoon was $8,000 RTW versus $15,000 booked separatly).
Hope this helps.
--Jim