Final Fantasy Tactics Advanced had Morphers who could shape shift into different monsters and use their move set.
Darn, I was gonna mention some sort of shape-shifting class lol.
Beastmaster would be an easy one since they could use Tamer as the Class and Beastmaster as the Job. They could use whips or something.
Chemist to Calculator would be another combo that I wouldn't mind seeing either. It could fill the gap of a healing class easily.
The only class that I would personally desire though, would have to be Puppetmaster. I don't know what class they could make to go with it, but they could do something requiring crafting classes leveled to a point. this could also tie into Chemist.
Wasn't Vincent from VII technically a Morpher?
Chemist would fullfill the vision that the original dev team had for crafters having a place in battles.