Size question: Dwarf Pixies and Horned Frogs

[Linds]

Now I cannot find any conclusive findings online about Dwarf Pixies. It seems everyone confuses the two ssp. of pyxicephalus What is the max size of these little cuties? Are they very active or can they live in smaller spaces? Also, what is the smallest ssp. of Horned Frog? I am VERY limited on space these days so I wouldn't want to get something that I may have difficulty housing at some point. I cannot believe the lack of info on Horned frogs on the internet. They really only seem to cover Pac Mans