Custom post types taxonomy question

Hi,

I would like to utilize the new capabilities in wordpress to create 2 types of post types. Writer – which contains the writer name and Book which includes the book name.
Now, I connect the two post types using the taxonomy writer name (or similar). The problem is, that when I create a new book, the writer name field needs to be a closed list of writers (which were previously created in the writers post type).

Any simple way of doing this connection ? of making one type of post type that can add tags to a taxonomy, and another type which can only select from existing tags ?

Please advise