Juku's good (IMO) but there's a connotation that it's a sort of after school program.
Juku would refer to the school as a living entity, like, the teachers and students would make up the juku and the actual physical space of the dojo would be something else. I think it would break down like this:
Let's say you're gonna name your dojo afer Tako (octopus)
If your dojo is the flagship of an group of dojos (or might be in the future) the association would be Takokai.
The school would be the Takojuku.
The dojo would be the Takokan.