744 roster out of SFO for an S/O ??? I think would give you lots of time off...................I may be wrong but apart from "Temp Basings" I think you'll find all s/o's are HKG based so about 3.5 years to upgrade to JFO and then you'll be on a regional fleet for some time to get as much handling as possible.............................so still based in HKG
Best guess...........6-7 years to get on 744 as F/O and get a base
sorry !!!