What you see in a theater on opening day, the first (or second, or third) time a print is run, is probably somewhere between 2K-4K quality.

Today, though, any film print will have been made from a 2K or 4K DI anyway, so it doesn't really matter. If you're only concerned about the most detail, see it digitally with a 4K projector.

I, however, prefer seeing something that was shot on film projected on film, for aesthetic reasons, regardless of whether or not the 4K digital theater across the hall has more detail or not. If it was shot digitally, it should be seen digitally.

Basically, I want to see it as close to the way it was shot as possible. Which is why I don't see films in IMAX unless, like The Dark Knight, at least part of the film was shot on IMAX.

But if you want to capture Star Wars the way it was seen in theaters in 1977, it's likely to be somewhere between 2K and 4K quality. Unless you saw it in 70mm, in which case it was probably above 4K quality.