Married or single ? Children ? Probably the biggest factors in deciding what's best.
If you're single and want a quick upgrade try Vietjet, possibly Tiger Taiwan.
Many countries won't accept expat F/Os and if they do promotion may be a problem. Get yourself upgraded ASAP and then you can pick and choose the more desirable jobs.
Start with Vietnam, Taiwan, China, Myanmar, Malaysia, Thailand in that order.
Forget Japan unless you can pass an astronaut medical and fancy spending 12-18 months doing your whole licence all over again.
Be careful with China, there are good opportunities but read through the other threads first.
Malaysia and Thailand don't want foreigners.
Cambodia may be worth a look as well.