Species suggestion

[TRD]

with that floor space you should be thinking about the smaller arboreal snakes... not pythons and whatnot already mentioned. Too small for them to be happy.

Rough green snake (insectivore species) for example. You can keep them in groups, are highly entertaining, but not a snake you can hold.. requires a bit of specialist care as they are insectivores, do need UVb because of that too. But fun diurnal snake to have.