I'd prefer to blow it up and trade Melo but here's my plan based on keeping Melo.
Draft Winslow 4th. He starts at the 3 and Melo at the 4. Target either Koufos or Ajinca in free agency, don't really care which one, should probably cost $9M-ish of our $26M available. Either of them starts at 5. Target Biyombo at about $6M. Worst case scenario he's a very good defensive big on the bench. Best case scenario he turns into Marcus Camby. That leave about $11M in cap space. Tell Jimmy Dolan to go **** himself and try to bring in Lin for around $5M or $6M. Throw the rest of our money at Lou Williams or Mo Williams.
Not really interested in Monroe who seems like a good stats on a bad team kind of guy. Like Shareef Abdur Rahim. Definitely not interested in Rondo who hasn't had a single positive moment on the court in 3 seasons. I like Tobias Harris but not at the money it will take to get him away from Orlando. Don't expect anything from Thanasis.
That gives us a lineup of
PG: Lin
SG: Galloway
SF: Winslow
PF: Melo
C: Ajinca/KoufosBench: Biyombo, THJr, Lou/Mo Williams
That gives us a very diverse lineup that allows us to match up with a lot of different teams. We can go big with Koufos/Ajinca and Biyombo up front, Melo @ 3, and Winslow @ 2. We can go super small with Lin-Williams-Galloway-Winslow-Biyombo. That's a team good enough offensively and defensively to be a top 4 or 5 team in the crappy East.