There is no way you'll get S-3. Very expensive to maintain despite being a very useful and versatile platform (I was lucky enough to do a sortie in an ES-3A from the Eisenhower many years ago). At the end of the day, it's a 1960's design.
As far as I'm aware, the USN have opted for FA-18E as their buddy of choice (a fact which has horrified the fighter dudes and is not, I'd imagine, a duty of choice!).