Hi sprewel1312:
I tried this path but ended up caring for the Fancy Guppies I got for this project, they even have names now... Then I did some more reading and decided to go with Convicts. Problem is I ended up caring for them too, so now I have two pairs living in two different tanks, and I let nature takes it course. Prolific breeders and great parents!
Using meds for feeder fish just doesn't make any sense to me... If I have a sick feeder fish I would like my other fish NOT to eat those. Preventive measures should do the work: Quarantine accordingly and raise your own fry. To pull this through you would need at least another tank to raise the newborns.
I first considered guppies since their pregnancy cycle last around a month and all you need to do for getting fry out of them is wish you don't. Mollies might be a bit more demanding (in terms water conditions). Convicts seem the best choice; if you get a male and female they will pair-off.
Since I failed in this, let's wait for experienced advise...
On a side note: have you considered hatching
brine shrimp (artemia)? it's a cheap and easy way of live feeding... just a thought.
Pepe
Santo Domingo