Most quality safes are all built the same. They're built to guidelines placed by the govt. and the insurance industry. Basically the ratings of safes are the minimums of how they are built. (door thickness, body thickness, group II locks, relockers, hard plate, etc.)
Take 2 safe companies that build safes that are comparable in features, you usually end up paying for the safe that catches your eye the most. If both safes area "rated" safes, they're built the same.
Do not buy a safe with an electronic key pad. They're prone to failure. Get a safe with the dial combination on it. It'll either be an S&G (Sargent & Greenleaf) or a LaGard lock.
Also, just because you buy a safe that has a fire rating on it doesn't mean everything you put in it will be protected. Fire ratings are in 'hours' and 'temperature'. Example, a 1 hour safe rated at 350 degrees is guaranteed not to exceed 350 degrees internal temperature exposed to a 1700 degree fire for 1 hour. (they say that home structure fires are usually out within an hour) If you are wanting to protect any type of media (tapes, disc, etc.), you'll need a 'media' safe designed to protect that type of stuff. Media safes are NOT cheap.
My .02
HTH
Dan.
(I use to own my own safe company. Really!)