After some more research on FT, I decided to go for:
SFO-LAX-HKG-NRT-SYD-SFO

I understand LAX-HKG route has the new CX business class seats, which is not on SFO-HKG yet. (Flying business is "special" enough for me that it is worth the stopover. And hopefully LAX has a nice lounge.)

Unfortuately, the stop in LAX doesn't give me enough room under the mileage cap to add MEL to the trip, but that's ok. SYD-MEL flights appear to be very inexpensive, and it also gives me the option of renting a car and taking a scenic drive.

Also thanks for the ExpertFlyer recommendation, which helped me in finding D availability on HKG-NRT. (I'll save NZ for another time; I have a good friend who is a native and would rather travel there with him. In the meantime, I have friends in Tokyo to see.)

I've called the AA RTW desk (and spoke to a very helpful and friendly CSR) and made my reservation. Thanks again for everyone's help!