You could check out the" Blue Acara " mine got to about 3 and a half inches , in 2 years before I traded them away. If you get a mated pair they get a little aggressive .As do most cihlids . Mine spawned in a community tank[ 70 gal] . Some other Acaras are also pretty good , as well as some of the Geophagus esp. "Jurapuri" mine was about 5 " . you could also look at "rams "," curviceps " or " african butterfly cichlids"a.k.a hemichromis thomosi [palmatochromis{? spelling} thomasi] sometimes called the "Dwarf Jewel Cichlid " only alot more pieceful . hope this helps . maybe not with guppies or neons, you could use a larger tank .