I think some people have this misconception that Dick Vermeil is soft because he cries after victories. This is untrue. Infact I remember vermeil getting in trouble in st. louis and kc for running one of the hardest training camps in the league. Basically he pushes his players to the max, and holds young players responsible. Look how larry johnson exploded shortly after vermeil told him he has to take off the diapers. It was a wake up call that served LJ Well. Vermeil gets the most of his team, and would be an excellent choice for head coach.
Turner is another guy like you said like gregg williams while lacking the ability to be a head coach in an excellent coordinator. I also wouldn't mind Joe Vitt from the rams. He seemed to adapt pretty well when given the opportunity to take over for martz and brought balance to the rams. He's also a runningback coach, so you know he'll like to run the run the football.
Singletary is interviewing for several head coaching jobs the way I hear it, so we probably wont get him. But I'd love this as well. I also wouldn't mind someone like Dick Jauron, or Jim Bates to fill the dc role.