Generally, I would not mix lizards in with darts, but if you have to, I would use CB Lygodactylus williamsi. That's if you can even find them. They are a small, diminutive really, turquoise-blue gecko from East Africa. If used they must be CB and parasite/disease free.
Now the three dart frogs you mention are all good beginner's dart frogs. Dendrobates leucomelas is probably the easiest to deal with because it is not nearly territorial as the Brazilian yellow-head/blue dart frog, Dendrobates tinctorius. Females of the tinctorius species can be very territorial and can kill each other, where leucomelas are a bit mellower.
Even though the blue dart and the Brazilian yellow-head are the same species now, you should not mix them in the same enclosure. You do not want them cross breeding and producing mutts. Unlike the snake hobby, the frog hobby does not look kindly upon hybrids and man-made morphs.