There are various Amphilophus species
You could just get a RD/midas, but there are also several others that are less common; a trimac would be nice. Lyonsi is also very cool, you might be able to keep a pair in a 75.
Herichthys carpintis 'escondido' is another very nice fish. Cyanoguttatus (texas cichlid) is another choice.
Any of the smaller Parachromis species would also fit, honestly I don't think a large male jag should be in a 75.
Cuban cichlids look a bit like a jag, and get about 12" long.
Also you could look at Paratheraps/vieja species. Some get a bit big, but there are several that have fantastic coloration.
I started with a green terror in my 75. He's getting towards 2 years old and isn't much past 7"
Great looking fish, but it would be nice to have something a bit bigger.