-3-4 kuhli loaches (see below)
-6-8 Cory habrosus (Like cooler temps, never had any luck with these)
-supreme Red cherry shrimp (always a great choice, get them breeding before adding a lot of possible predators and provide a lot of moss/cover)
-a small schooling fish -probably CPDs or another small Danio. (Will prey on shrimplets, changing these out to a Bororas species might see better results)
-a few ottos (hardly ever go wrong with otos, Nerites do a terrific job with algae as well)
I myself like Kuhli loaches in a densely planted tank (we have 4-6 in our and never see them other then feeding time) and have heard in softer water tanks they will accidentally breed on occasion.
I have never bred the zebra otos, there should be articles online and most likely similar to the normal ones. I'm guessing very low Ph and soft clean water are a must.
"In the land of the blind, the one-eyed man is king" Desiderius Erasmus