organisationally we always seem to try and elevate internally - mike mcdonald was probably gonna be the next guy but he left this offseason - and now there's lots of options...
Rob Ryan and Anthony Weaver both have previous experience as DCs in the league (and Ryan especially has some links and similarities with Wink philosophically)
But to me it seems likely that Chris Hewitt would be the next guy on defence - they've been steadily promoting him and increasing his role every couple of years to try and keep him around - my guess is he's the next guy in waiting and just like Wink had his own ideas about freshening up the defence stylistically he probably also has his own (especially having worked so closely with the DBs for so long)
my thinking on offence is that if we're changing something it's because we need or want to make some drastic changes and that, to me, would suggest needing to bring someone in from outside the building with their own ideas and scheme - but it's not a bad position to be in - id imagine there's a lot of OCs who'd love the opportunity to design an offence around a playmaker like lamar