Well, a lot of people will tell you that kenyi really need at least a 75gal tank, and I tend to agree for the most part.
Numbers are only good if you end up with one male and two females of each, which I'm assuming you don't know at this point?
Even then, if you're going to do kenyi and auratus, two females is no where near enough for the most part. I'd up it to at least four females with just one male of each species. Adding a couple extra female estherae (red zebra) as well couldn't hurt.
Those three species are a very volatile mix however...two extremely aggressive species (kenyi and auratus) and one typically very aggressive species (estherae) in a tank that really is on the small side for all three - too small in my opinion for them to likely do well together as they mature.