Be careful with guppies from petco/petsmart. In my experience they are almost always carrying disease, even if there are no outward signs. I've brought several home only to see them slowly waste away and die in the next couple of weeks, and right now I'm dealing with parasitic worms that I strongly suspect were introduced via the guppies. Don't be like me - quarantine for at least a few weeks.
Meanwhile, the endlers I bought on Aquabid are amazingly resilient.