McMaster ships worldwide. If there is an issue with strategic materials or prohibited export because of governmental relations between your country and the United States, it is unlikely that any other US company will be able to help.
Countersinks are a very common commodity and should be available at almost any machinery supplier. McMaster does not carry anything out of the ordinary, in this regard.
Good luck in your search.
It is better to have enough ideas for some of them to be wrong, than to be always right by having no ideas at all.