Hi,
The Club Praia da Rocha
was A/I, but I'm not certain that it wasn't 3*.
The Paraiso de Albufeira is definitely 4* and does an A/I option.
You may have your reasons for looking for A/I, but you'll miss out on so much in the way of really good restaurants and bars on the Algarve if you tie yourself to one hotel.
Whatever you choose, enjoy !!