I like Anthony, though I don't think they could sign another FA if they traded for him. They might be able to get him on the cheap because of his contract, or meet the Knicks halfway in salary. He looks like an option C, if they can't get any big scorer who is younger. But keep in mind, those top FAs are going to be more expensive than Melo.
What they really need is a rebounding 4 or 5. Somebody like Millsap or Griffin, though Griffin is looking pretty fragile right now. They might even go after Cousins, if NO decides Cousins-Davis doesn't work. The big center might solve all of their problems. Drummond figures in, too.
They pretty much have the weapons to get most of these guys. All it takes is the willingness to make these deals. And to accept what their problems are.