I second, or third what has been said above about getting bigger than you think you need. I am currently using a custom safe from Halls Safe Company in CA. I bought it when I was living out there, and I got it through the local gunshop. I am not sure what their delivery policy is, but their customer service cannot be beaten. See, I got mine used, and had a few questions, so I called the company. I didn't get some phone service guy, they put you through to the company owner / president. A couple times I had to leave a message, and sure enough, within the hour, I had a call back from him.
I have talked to a couple guys that had safes go through house fires and their guns did not fare too well. I am not sure what kind of safe, or exactly what the rating was, but t doesn't matter, they still suffered damage.
For a good deal, check around locally with the locksmiths. I know that a few locksmith stores that I have been in have carried safes, both new and used. You can probably find a good deal on one there.

Good luck..