If you want to include a bubble nester in your study I would recommend the Paradise fish.
I have had them literally nest and spawn when I just put three in a tank to help keep it cycled while I was waiting for some fish to come in.
The requirements are :
a) still surface water or plants under which they can put a bubble nest on the surface.
b) raise the temp a few degrees above thier norm.
That seems to make them think it's springtime and time to spawn.
You already have mollies in for livebearers, which I think are in fact the easiest overall fish to breed.
Cichlids - after many years of different species it was my 90g of mixed cichlids that breed quite accidentally. One day there were tiny fry in there. How they survived in that overstocked tank is a testament to the care of the territorial parents.
PS earlier failures could have been the terribly hard water we had that prevented other species from breeding.
I was also hoping to breed some guppies or rosies for feeder fish, i was wondering what i would need to do as for setup and care of fish, and also how do you sex guppies and rosies?