Out of that list, I wouldn't mind taking a flyer on a young big (Robinson) or Kendrick Perkins/Samuel Dalembert (would prefer Perkins out of the two though).
Backup PG is obviously still a need, but a backup big remains a far greater need imo. There are several players on this team (Irving, LeBron, Delly, Shumpert) that are capable of running the point. If they did end up getting a backup PG, I wouldn't be surprised if they brought back AJ Price since he is already familiar with the team. Nate Wolters would be another decent pickup for that position.