H+ is short for HSPA+ which is also known as 4G or 3.5G on some carriers. That's what you want to see on your phone, so I wouldn't be getting too worried.
Just to clarify further, if the Korean carrier does not offer 4G or H+ or whatever you want to call it, no SIM card will do it. You first need a phone that supports H+, then you need a BlackBerry data plan from a carrier that offers those speeds on their network. All I can tell you is if you're getting H+ on your homescreen, you should be very happy.
