I'm not a big fan of the more traditional centers in Vucevic and Koufos, especially Koufos, who I don't think would move the needle for us. Vucevic would certainly help our rebounding and interior offense, but isn't he pretty terrible defensively and always giving up major numbers to opposing centers? I also don't think he'd be worth giving up anything significant for. And what's the deal with everyone's obsession with Nurkic?
I think we need to sort of transition back to our defensive identity, which is why I think someone like Noel is the best trade idea for us. He'd certainly come fairly cheap (thinking around Rozier, Young, and the Memphis pick) and he's exactly what we need in a young, athletic, defensive big who is very mobile and an excellent rebounder.
And I'm okay with trading for a big, because I really don't see us upgrading much next year during free agency. I think the major players in free agency come in three camps:
Not going to seriously consider us or leave current team - Griffin, Paul, Curry, Durant, Lowry
Too old/not worth the money they'll get - Ibaka, Milsap
Attainable, but not in a position of need - Hayward, Holiday
I don't think maxing out someone like Hayward would really help us all that much. I'd be okay with giving Noel a sizable contract and drafting a high-level big with the Brooklyn pick to develop under Horford and Noel.