16-35mm on FF ideally, any wider and you're in fisheye territory, which could be fun, but not as the only lens there.
I'd take camera/lens on tripod, trigger in one pocket, extra battery, memory card, and cloth in the other. That's it.
As I mentioned before, the light shafts aren't there long, and only when the photographer only tours are running, ~10-12, which I guess varies a bit throughout the yr.
