A bit of a mixed bag here, but IMHO there are obstacles to each.
Thailand: You don't need to be a Thai national as long as the job requires flying Thai registered aircraft (big hint).
Thailand private pilot validations require lots of document filing plus a check flight. Not the sort of thing you can do over weekends.
Hong Kong: You need to be airline sponsored, otherwise you can't just roll up and register. Furthermore, there're lots of detailed requirements in the regs (CAD54). You won't believe these until you see them.
Singapore: Do you have at least 700 hours total aeronautical ? If not, then you aren't even eligible to convert to a CAAS CPL.
That's a good start, isn't it ? Try and do your own research. Don't just listen to my BS.
