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Get a TL rated door. Hard to find and expensive but over the years the amount of money you will have in that room will be 20-50 times that much.
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In my opinion, anything rated TL-15/30 by UL is going to be much heavier duty than the non-rated doors. The constitution methods tend to involve lots of thick steel plate and strong bolt work. Just remember that the vault walls probably need to be poured reinforced concrete to match the protection provided by a rated vault door. A vault should be a system without obvious weaklinks.
If you're shopping in this segment of the market then Brown and Graffunder might also be worth looking at.