Korea is THE plate to get springs. Best you guys check out their forums (KBmania, OTD) for the spring purchases. I'm actually surprised you came on this forum asking for Korean springs. I personally prefer really light springs, so 55g or under. I think most people would prefer ones that are a tad stiffer than stock red springs, so around 62g-65g.
Oh my day (night right now) is just dandy. Enjoy your stay here!