I couldn't agree with subrosa more. I got into livebearers a bit when I moved to the coast where we have hard water, even put them in small tanks on the porch outside. The colors were awesome.
Most states or larger cities have freshwater clubs where you can find people that breed the more colorful livebearers that are harder to find at most stores.
The Neolamprologus cichlids are also quite fun and ready breeders. Brichardis, brevis, leleupi, multifasciatus are all found quite readily in most stores that sell cichlids.
Neolamprologus - Wikipedia, the free encyclopedia