I would say the important players to keep are, Brezovan, Ifil, Easton, McNamee and Cox. Oh and Peacock
I wouldn't be overly fussed if we lost any of the others.
I forgot McNamee, but he also has a contract to keep him here so will stay, Easton is very good at this level but not sure he would be a level up, Peacock is getting on a bit and probably only has one more good season in him, Ifil has had a shocking end of season, hard to understand really because I thought he was one of the most outstanding defenders in the first part of the season in this division, but that really sums him up, not good enough for the Championship.