Gonna be honest, as much as I love godzilla I really don't know where all this is coming from. To represent the series in a satisfying way, you'd need a higher budget and space to the point where you'd be better off just making a permanent attraction. Like even considering a stripped back budgetary effects situation, like a less advanced Kong, or more similar to stay puft, I really don't think it would do it justice, especially when you consider godzilla himself is significantly larger than both of them. Unless you want a bunch of injured civilians and a big static godzilla head at the end, I just aint seein it.
Probably more realistic to assume the Japanese creatures house is just gonna feature much more human-sized mythical creatures from Japanese folklore if it happens, think more Shadow Lands at Knotts