New Leader

No-one with any sense or ambition is going to want to replace Truss when there remains a large cabal of ERG members in the Parliamentary Party and the Tories are likely to be decimated at the next General Election anyway. 

A serious contender (if Truss hasn't already threatened an immediate GE if she's unseated) would want to launch a leadership bid after a GE, with a rejuvenated Parliamentary Party shorn of the ERG members who have been the cause of all the current problems - providing that person retains their seat.

Ergo, any person selected by Tory MPs as a replacement for Truss is destined to be merely a caretaker PM and not someone likely to turn around the ship of state within 2 years.

Anyone in the current Cabinet is far too tainted by association with Truss.  

Boris Johnson? No - he's too lazy to clear up the mess, despite the wider Party members wanting him, and Tory MPs are sick of defending him in the morning and being shown up as fools for doing so the same evening, which is why they got rid of him in the first place.

Theresa May again? Possibly - even if only to get one over on Johnson.