I would HIGHLY prefer Cousins to Griffin.
It makes no sense why Cousins wouldn't be available. They have very little chance of even making the playoffs this year, let alone contend any time soon, and the longer they hold onto Cousins the less valuable he gets in return. They could legitimately jumpstart their rebuild with good pieces and picks to build around. Even a package of Amir, Smart, Brown, and the 2017 pick for Cousins and Collisin/Mcelmore would give them one of the brightest young cores in the league with Smart, Brown, WCS, Skal, an almost sure fire top-3 pick in 2017 and another probable mid-lottery pick with their own pick or the Philly swap.