No, GD does not support IDNs. The best is domainsite.com thats what most if not all the big players use. If you want to consider someone else, idotz is not bad or dynadot. The problem with dynadot is that they keep your money as credit if a name is not registered since for idns, sometimes it shows as available but is not. Thats why I recommend domainsite because they don't charge until registered.
Good luck!