GBAX have 100% English GP32's, the only Korean is in the Free Launcher, which will be the same where ever you buy the GP32 from. GBAX is a good place to buy, it's in the UK, so apart from VAT what you pay is all you'll pay, and Craigix (He runs GBAX) really cares about the scene and posts on here too. From overseas you could get stuffed for Import Tax, although most importer put the price below the threshold on the customs notice, I think they just miss out the hundreds digit by accident.
I hope that this helps
MrT