Larry Nance Jr.
Danny reportedly wanted him instead of RJ Hunter in the draft, but the Lakers took Nance one pick before us. (Forgot where I read that, but I will try to find the source).
Nance is starting to look real good in LA, so I doubt they would move him, but they seem committed to starting Randle over Larry.
I think finding a young (ideally), overlooked player to pair with Horford would be the best bet, as it could save us from using our top assets and hopefully we would have the player under contract for a few years before having to pay up.
Nance and Portis would be my targets.