I'll recommend getting rid of the frontosa, the jaguars and the green terrors. The peacocks and labs will get along fine in the 75, though the tank will be at upper stocking limits and you will need to be on top of water changes and filter maintenance. The frontosa may do alright, but they are large fish (8"-13", depending on sex) and really should be in groups.
A 75 is the absolute bare minimum I'll say is acceptable for a single jag, though I say that with reservations and wouldn't recommend it. A female is gonna hit 12"-13" easily, males larger. They are also not going to tolerate the other fish once they start growing out. IMO, few Africans can hold their own with a large CA cichlid. The green terrors are SA in origin and will get about 5"-10", again dependent on sex and care. In spite of the name, I've always found them to be less aggressive than their reputation. They like having their space and don't respond well to the overcrowded conditions typical in African tanks; they will be much happier in someone else's tank.
As far as I can remember, don't recall frontosas ever bein' considered a "hap" by hobbyists; few of the Lake Tanganyika fish are or have ever been. Regardless, they are currently in their own tribe (Cyphotilapiini) in the subfamily Pseudocrenilabrinae, and are from Lake Tanganyika rather than Lake Malawi.
WYite
