Personally I would do this.
Sullinger+Green+Vitor Faverani and 14 first round pick, and the 2015 Philly pick that is essentially two second rounders, and Miami Heat second round.
Green is a definite improvement of Brewer, who can't score as well, but can only defend. Green is a way better upgrade, and can or can not be the 3rd or 4th best player. Sullinger is already proving his potential, and he's 21 on a two year friendly contract. They get our draft pick this year, and use that as a good building block for whatever position they need.