I was in your same boat about 3 years ago. I needed to buy a fire resistant gun safe for storing all my "toys and single use batteries for said toys"
I looked at both the liberty safes and the champion safes. Both are strong competitors and from what I have found, very similar in protection for everything that I store in them. What it came down to for me was there was not a company locally that sold Liberty safes but there was one that sold Champion. So at the end of the day, I went with Champion. Another point that sold me on Champion was that it had the door holders as standard and I would have had to buy one for the Liberty. SO those are the 2 factors that sold me on the Champion.
Now I would like to offer some advice. The champion safe that I purchased was a shallower unit so that it could fit in a specific area of my house. My advice for you is once you know where it is going, make sure to mount it to the floor. The last thing that you need is for some bad weather to come and launch it into space. (I live in southern indiana so naders are a real possibility)
Another thing to think about is the finish. I hated the high gloss polished finish that my fathers Liberty safe has due to fingerprint smudges and having to keep it looking clean. I went for the bedliner look so that i could avoid having to clean it as much.
And i agree with 74Rallye. Always get one bigger than you think that you will ever need. You can always store other valuables inside of it. (documents, jewelry, "single use batteries", booze, etc.)
Good luck with the purchase!