Seoul and Busan probably have the most developed bouldering areas, though Jeju is coming up with more and more and harder and harder. Rocks are to be found pretty much everywhere. I'd suggest you consider the job, and if you find a good one, check out the bouldering scene nearby. If you're happy and have more free time you'll see more boulders than if you're overworked and have no time. Also. . . are you a city girl? a country girl?
"If you can't do something well, you might as well learn to enjoy doing it poorly."
-- from a de-motivational poster, but I find it oddly liberating