I agree great fish BUT, a 75 is temporary , I am currently using a 75 for a grow out tank for 12 fry. In my experience Festae at one year are about 8 cm, 2 years 14- 18 cm and by 3 years the males are 20+ cm. The smallest tank I would use is a 210-220 for a pair. I think best size for max growth is 285+ gallon. If I may add, for your consideration, Festae seem to have a larger territorial requirement than the other Chiclids I have had. My opinion is that they are more assertive than overtly aggressive and there is a direct relationship to territorial space. If you get a pair they need space a lot of it. Stressed uncomfortable fish=less chance of breeding. These are great fish my favorite also good luck my friend.
To answer your specific question a 75 gallon will work in the short term, year or so, but if you want to raise and breed these fish think big - 220 plus. Also dont forget about a divider solution!