I agree with Randy in that worrying about the fire rating isn't a high priority. Most FDs won't get a house fire out in less than 30-45 minutes and they won't let you go back in to get anything, anyway.
I have a Cannon C35 and love it. Nothing bad to say about it other than I've outgrown it, but I guess that's not the safe's fault! I have one of the pistol holders that slips over the top and bottom of the door cover and it works great. No warranty voiding with it. On that note, one of the biggest things to look at is the warranty policy. That's why I have a Cannon. Its been YEARS since I've researched other brands, but at one time, with most brands (except Cannon), if you had a warranty issue (attempted break in, for example), you will have to pay to have your safe shipped back to them (usually around $250) and then pay another $250 to have it shipped back to you. If you never have a warranty issue, its no big deal. If you are unfortunate enough to have a warranty issue on a good quality safe, you are another $500 invested. With Cannon, they cover ALL shipping costs for ALL warranty issues. Other safe companies may have stepped up to compete with Cannon on that, but I strongly encourage anyone to research the warranty over the fire-rating.
That, and like everyone else is saying, get bigger than you think you need. I'm trying to convince my wife that another gun safe is exactly what we need before stuff gets piled in closets and under beds.