Some thoughts:
I think Sammy should be a top priority. Nene, a second. The team needs a C who is athletic, can defend the rim, and can be physical. One of the limitations of Cousins is that while he's a big body that can take up space, he doesn't have that much lift, and isn't an above-the-rim player. I think this is one reason why JJ might compliment him on the floor, as he's far more athletic. Dalembert is a long, athletic, mobile shot blocker who can play with Cousins and help on the defensive areas in which Cousins doesn't excel.
Regarding Chandler, I don't think he's a good fit, and here's why: while he's a great above-the-rim offensive player who can finish lobs and grab offensive boards, he's not an above-the-rim defensive player. I've watched a ton of TC with the hornets when he was playing some of his best basketball, and with Dallas this season. He's very mobile (when healthy) for a 7 footer, and is a good pick and roll defender. But when it comes to protecting the rim, he's not in the same class as Dalembert. The one negative about Dally in this regard is that he often tries to help too much, giving up second chance points to his man that he left to challenge another shot around the basket. Also, Dally's offensive game, while limited, is still far superior to TC's.
So, the Kings get the better deal in Dally IMO. He's been more healthy, is better offensively, is the better shot blocker, and I think he fits what the team needs with their frontline rotation. If they don't get him, I would consider Nene before TC.