If we are going to go all in for a ring next year, I would think we'd need to bring in:
A point guard who can run second unit offense and start/close alongside AD/LBJ. Someone like Jeff Teague and Dragic would be ideal. Reggie Jackson or DJ Augustin is fine too if we can't land the top guys;
Some depth on the wing who can shoot, defend and has the athletic/physical profile to match up against guys like Kawhi and PG. Batum looks like someone who can be had for cheap and might ring chase. His versatility would fit in well on this team. Glen Robinson would be a good fit as a 3 and D, so will guys like Justin Holiday or Kent Bazemore or Tony Snell;
I would try hard to retain Howard and DMC, because I think they bring different elements to our team. Neither should be all that expensive to keep, so why not. Markieff, if he wants more money, is probably a goner. Maybe we can make a run at someone like Giles or Saric for upside, but we should be mostly set as long as DMC and Howard comes back;
The one big move that I think could happen is trading Kuzma. His fit on this team is questionable and it showed on the court. I think, we might be able to do a sign and trade for Otto Porter with Kuzma and Danny Green going the other way. Porter is a long wing who is a good 3 and D player and has upside to be more than that. I would also look at someone like Buddy Hield. He is a bench warmer on a huge contract for Sacramento, but his shooting and play making would make this offense lethal.
Just my two cents on the offseason. I think we CAN get a lot done, since most teams are saving cap space for 2021. But we will see how everything shakes out.