Double wielding human paladin sub hunter with Peytral, Nagrarock, sequence(80 or higher), ninja tabi, and the angel ring is the embodiment of pwnage. Sonic boom>far fist(its just enough to kill almost any enemy in the game when you are at high levels). And, you can gain 10jp in a single attack. The only thing you could argue would be better would be to replace double wield with attack power +, which would allow sonic boom more power, but you still won't have as much move.
Morpher is potentialy the strongest class because it can deal 999 damage if you feed your monsters enough, but otherwise, sages are godly. Turbo mp makes them extremely powerful both physicly and magicly. You can just about sub any job for it. If you're Sapere Aude is powerful enough, then you should be illusist sub sage, as magic at that point is so brutal it isn't funny.
The reb mage is a good class once you reach level 50. Raise the viera as a summoner/white mage, then switch them to red mage for the better move. Red mage sub summoner is awesome.
Gunner sub mog knight gets many status inflicting skills, as well as the power of ultima. Time mages and Jugglers also have some good skills.
Any banga needs to sub Gladiator, and stay far... far away from bishop. Monks aren't that great, either. Templer/Dragoon sub Gladiator is best.
I am Cylun. May your life be easy and your future ripe.