I can break this down in a pretty simple way. Kyrie is no dummy so will go to the best situation. The best to me is to team us with Davis in Boston. He gets the most money and to me, the best chance to win.
If the Celtics cannot get Davis though, his best chance is to go to where ever Durant goes. I don't know where that will be, maybe Kyrie has already talked to Durant and knows, but teaming up with Durant is a very good situation. He gets less money and has to move to a new team/city but otherwise, still are really good deal for him.
Now if the Celtics can't get Davis and Durant decides to stay with GSW (a very unlikely combination of scenarios in my opinion), then I have no idea where he will go. Maybe team with Kawhi with the Clippers? Maybe still stay in Boston?