Stones is the obvious choice right now, Sterling is probably just another player who he will bring the best out of, same as he will with everyone, but Stones is in a position that's so important to the Pep system that he's going to need huge amounts of coaching to reach that level of perfection Guardiola demands, so it follows that he's gonna get a lot of 1on1 time.
Also I think Aleix Garcia is a good shout. Busquets, Hojbjerg and Kimmich were all defensive midfielders that Pep took a shine to - stands to reason that he sees a bit of his old self in these players and as it's the position he knows best himself, it's the one he can really teach to these young players. Garcia is in the same position and his rare passing talent is something Pep will latch onto.