In an aquarium as large as 150 gallons the options will open up immensly, however I still would never put Iodotropheus in the same tank is Chipokae.
Melanochromis Chipokae are as aggressive as mbuna get, and you must be very careful in your selection other mbuna--varieties such as Iodotropheus may have problems handling this aggression, even in a very large tank. To deal with this hyper-aggression it would be best to also stock many females to each male, as many as 10 or more would not be unheard of.
Auratus would not be a good choice at all, they are much too similar to Chipokae, and aggression issues will be amplified because of this. Choose one or the other, but not both. On the smaller end of your choices (75 gallon), I would not go with either of these varieties.
Good luck,
TCA