Asia Miles redemption is based on total travel distance of all flight sectors. The one-way shortest distance is 8169 miles (16338 miles return) already, which falls into the award zone E (7501-10000 miles one way) in Asia Miles and require 90,000 Asia Miles. FYI, travelling from SFO also falls into award zone E.

Of course, you can top-up by paying the gap if you have 70% of the miles, in this case 63,000 Asia Miles. The cost of it is $60USD for every block of 2,000 miles.

Possible routing with 60,000 Asia Miles (award zone D) is to travel from Vancouver. Get a separate ticket from LAX to YVR

You can do
YVR-NRT-SGN on JL return
YVR-HKG-SGN on CX return
or mixing CX and JL is possible.
YVR-HKG-SGN on CX,SGN-NRT-YVR on JL
YVR-NRT-HKG-SGN,SGN-HKG-YVR routings are also possible.

Routings on Air China and China Eastern are also possible.

Do check availability, taxes and fuel surcharges.