Surrogate Key As Parameter In Stored Procedure?

I have two tables:

countries(country_id integer, country_name string)
authors(auth_id integer, country_id integer, auth_name string)

...Where "country_id" in the authors table refers to the same country_id in the countries table.

I want a stored procedure to handle the insertion of new rows in the authors table. There are two methods of doing it:

1) CREATE PROCEDURE addAuthor( authorName, countryId )

And

2) CREATE PROCEDURE addAuthor( authorName, countryName )

Now, I like #1 because the implementation is simple -- the calling code simply passes an author name, and a country id and an INSERT INTO statement is called with those parameters

INSERT INTO authors( @authorName, @countryId )


I like #1, because it hides the surrogate "id" key from the application calling code. But on the downside, it has more overhead work, because you have to first a) verify a country with that name exists, and b) select that id into a variable.

DECLARE id INT;
IF EXISTS (select * from countries where country_id = @countryId ) THEN
SELECT country_id INTO id FROM countries WHERE country_name = @countryName;
END IF;

(Sorry I may have the SQL syntax wrong up there, but I was just trying to demonstrate the extra overhead involved).

Which approach do you guys think is better?