You can only stopover in the international gateway city on AA miles, the first place u fly into from overseas. So for the return you would want to look for space from NRT-ORD (JAL) or HKG-ORD (CX). There are also AA flights from PVG/PEK but I prefer CX, JAL second. I flew ORD-HKG and felt it was quite nice (though 16 hours).

You can also layover (< 24 hours) in a connecting city. On way back from China I spent a day in Tokyo, since I love getting sushi there. Mainly stayed in Ginza but saw a part of the city (Odaiba) that I hadn't had a chance to go before. One note if you layover in Tokyo try to fly into Haneda because Narita is faaaaar (on exit you will have to fly out of NRT).

You would book that using AA miles. As Spacetime above stated search BA website and call american airlines.

One more suggestion, if you want a stopover in HKG, you can book say:
ORD-HKG (open jaw)
BKK-HKG-ORD(stopover)-SFO
and then book a flight from HKG-BKK on with cash as it is fairly cheap.

I do get not spoon feeding info if they don't want to try looking first. But why just hint at the blog, and not link him to it? lol

Anyway I would help, but I never booked any award flights my self yet. (Actually need to learn the in & out of booking with miles getting the most value my self.)

The way I look at it not trying to take away business from award booking services.........BUT assuming this won't be your only trip I would try to read up, and learn how to do it your self. People collect miles, and points to save I assume. So why not save on the award booking services also?

The best karma for miles is when they are redeemed.
My 2 cents:
1) If you can provide more specific details like exact airports including choices, dates etc FTers will lend a further hand. :)

2) Since US Airways allows only redemption for roundtrips I feel you do not get any values of the 40K for this trip.

3) Search for "Booking with avios like a pro". A series of posts with a LOT of information will come to your feet.

4)Thai airways has a very good service in economy as well. I would say prefer them during one of the legs.

5) Last but the most powerful tool I know, get familiar with expertflyer (search this as well). Start with a free trial for 5 days to play with it. If you do not find availability in the regular travel pay for a month subscription ($10) and save alerts. These are your life savers.

6) Be prepared to call the call centers multiple times and make sure to be nice even if you hang up on them to avoid them making notes on you. :P

7) If nothing helped or you were not able to do above due to your limitations on time, enthusiasm, patience then try for award booking services. (Honestly your itinerary is relatively simple and your dates are also not a bad time to find availability towards Asia as well).

I did simple ORD-BKK-ORD searches for award availability during Dec 13 and Jan 14. Availability looks very good.

http://i40.tinypic.com/e0r39.png

http://i42.tinypic.com/731mxw.png

I will try to do more on the AA searches as well and post results.

I did not include the exact links for what I was referring to, since they will point you to the same specific info I already know. A general search could land you in a better spot at times.

All the very best.

I think you'll find that while availability looks good on United, the routings are terrible (multiple and lengthy layovers). You're probably better off saving those United miles for a Europe trip and using your AA miles here.

ORD-HKG-BKK (Cathay) and ORD-NRT-BKK (JAL) are both available on the outbound leg, and JAL shows availability on the return.

Yes, ExpertFlyer can be useful, but in this case you will do fine just using the British Airways site (and AA.com for your free one-ways).

If you fly Cathay on your outbound leg, consider adding a stopover in Hong Kong and using 7500 BA Avios to continue to BKK.

thanks everyone for all the info and suggestions. i will be pretty busy in the coming weeks learning about award booking.