If anything I can see Mbappe signing for PSG.
1)His family is from Paris. His father and friends are pushing for him to go to PSG. His mother wants Madrid. Personally I think Monaco, PSG or Arsenal are good places for Kylian.
2) Signing Neymar would be a huge statement of intent from PSG, I can see Dembele moving back to France as well.
As for Neymar's replacements:
The closest one with Ney's play style and potential output is Dembele but Barca won't get Dembele this window, he's not yet ready.
Dybala isn't a winger.
Hazard isn't feasible. The guy doesn't strike as a huge competitor, he's comfortable at Chelsea and Chelsea are a good club in a good city anyways, earning a good Salary he has no real incentive to leave.
Hope Barca enjoy Delofeu and Paco tearing up the wings, who knows that dumb board might buy Pedro back from Chelsea.