I would stick with other White's, as Don said any smaller species are likely to end up being a meal. There are several morphs available if you want a little variety (Australian blue, Indonesian green, and blue-eyed). I have also heard/read many times over the years that they cohabitate well with white lipped tree frogs (Litoria infraenata), but I would suggest talking about it with some more experienced keepers since I don't work with either species.