Any of the movie set in Tombstone?

I wouldn't think so... seeing as Dora Hand was murdered in Dodge City and it happened years before Earp landed in Tombstone, but seeing as they're already playing around with the truth, who can say for sure?

“Sit at my right, and I may smite you; at my left, and you can stay to watch me rule the world.”

No. With such a limited budget it's just some movie lot in California. I've been to Tombstone.