Circle Pacific rules are on the OW website -

http://www.oneworld.com/ow/air-trave...e-pacific-fare

It comes in 22,000 and 26,000 mile flavors (for 29,000 miles, you have to include South America).

Prices are on the same OW website page. ($5,500 and $6,600)

You must cross north/central-Pacific in one direction and south-Pacific in the other. To meet this rule, you'll have to return from Australia/New Zealand.

You can check mileage here - http://gc.kls2.com/

Of your suggested routes -

SFO-HKG-SYD-SFO (18,924 miles)
SFO-HKG-NRT-SYD-SFO (21,031)
SFO-HKG-SYD-NRT-SFO

The first two should work. The last one won't because you're crossing north/central-Pacific in both directions.

Try -

SFO-HKG-NRT-MEL-SYD-SFO - 21,684 miles. trick is to stay under the 22,000 mile cap.

You're allowed 4 stopovers on the 22,000 mile version. Maximum of 2 in any one region and 1 in the country of origin.

Book by calling the AA RTW desk - 1-800-247-3247.

Check flight times and availability on ExpertFlyer. You need D inventory for business class.

********* edited to add
Following eireman's good advice to consider NZ,

sfo-hkg-nrt-syd-akl-lax-sfo

is 21,800 miles.