Scalley has his issues from the past, but time heals wounds, so I think he's most likely
Sitake might be hired away from BYU if he does well - Utah can pay more and Sitake has history at both
Brian Johnson is a great choice, but may rise too fast and be hired to a more prestigious program; he's a hot name in the coaching search
Sharief Shah is the other option or someone completely unaffiliated
Honestly, I think any of those 4 are good bets to maintain