If your visitors are from Korea it is always a good Idea to host your site in south Korea, the location of your host and visitors is important in downloading,uploading and speed of your website. You can even host at least one subdomain (just the part of your website which is visited by Koreans)
In korea you can hardly find any web hosting company with proper English support or English control panel but have at look at
Internet Brothers south KoreaWeb Hosting in Korea
they offer hosting with complete English support and panel like US hosting companies. Also make sure you visit their discount coupon page . I think they can help you in many ways too .