First name that likely pops up on people's radar next year is Greg Roman since he was shut out this season. You could rightly expect Lovie Smith to be a popular option too. Ken Whisenhunt will be looking to get back in the game. Maybe Josh McDaniels as well.
If you mean the Panthers specifically, it'd depend on whether Gettleman could convince Richardson to look at something other than just defensive coordinators, though for all we know that may be his preference too.
I'd add Jay Gruden and Zimmer (CIN O/D) to that list. Darrell Bevell (SEA O) was a finalist for a job and interviewed at a few other places. The NFL may retest guys like O'Brien at Penn St. and Kelly in ND should they keep things going there. Younger names that could get in the mix: Kyle Shanahan (WAS OC), John Pagano (SD DC)