Terra with Offering + Genji glove: She has awesome base stats, equips the minerva and heavy armor and weapons, and has the ever awesome morph.
Damage per round: 80,000
Celes with Gem Box + Economizer: Can equip minerva and heavy armor, Runic completly shuts down magic using monsters.
Damage per round: 50,000
Total for party per round so far: 130,000
Cyan with Genji Glove + Economizer: If you cast quick than there is no harm in waiting for his sword techs to charge. Combine that with a four hit tech and quick for a total of eight hits and you get a whopping 80,000 damage without use of the offering.
Damage per round: 80,000
Total for party so far: 210,000
Gogo with Running shoes +Genji Glove: Have him mimic Cyan by using the running shoes to make sure that Gogo is ready when Cyan is. Tacks on another 80,000.
Damage per round: 80,000
Grand Total for Party per round: 290,000 HP
This group has the potential to easily do about 290,000 damage per round. Considering the fact that the absolute max HP that anything could ever have is 65,535, I think that 290,000 is a bit more than you could ever need, but hey overkill is fun.