Unsure if the Gators would remove Mullen before Grantham or at the same time but who knows.
As for the list
James Franklin: Has experience with SEC (back to back 9-4 seasons with Vanderbilt) plus maybe a Keegan Michael-Key appearance or several.
Luke Fickell: Doing good in Cincy but was the reason why Ohio State hired Urban Meyer (he was 6-7 in 2011 as Suckeye coach).
Joe Brady: SEC experience (LSU during the 2019 season) and from Florida but no head coaching experience and doing so-so as Carolina Panthers OC
Mark Stoops: Had stops in Florida schools though I doubt he leaves UK
Jamey Caldwell: Having success in Coastal Carolina but unsure about coaches in lower-tier programs after McElwain
Also, I have some suggestions
Brian Johnson: Gators hadn't been the same after he left for Philly but no head coaching experience
Charlie Strong: Could be available after the 2021 season and was a Gator coach for a game however his tenure in Texas and South Florida didn't end well