I have sold and serviced safes for 20 years. We used to deliver and install but thankfully we don't any more.
Can't go wrong with Liberty. Same can be said for Cannon, American Security, Fort Knox, Gardall, Browning, and National Security. Stay far away from Sentry and Winchester carried by Costco.
Some things to remember. Gun safes are classified as a Residential Security Container. But don't let anyone tell you they are less secure. A quality gun safe is far more secure than any one person will need.
Check the warranties offered. Some will offer free replacement/repair in the event of a fire or burglary. But some will make you pay for the shipping.
Have it delivered and installed. It's well worth the money. Have it installed during the week when neighbors are away at work.
Definitely buy one size bigger. You or your family WILL find more to put in it when you go on vacation.
Media such as flash drives, CD's, DVD's, backup drives, film, negatives will NOT survive a fire in a gun safe. They require a much lower temperature to survive a fire.
SO......... Buy one of those fireboxes from Sentry commonly sold at Walmart. Put those items inside and THEN put it in the gun safe. These items require a double insulated safe. Figure out what size box you need and then where you will put it in your new gun safe.
Buy a dehumidifier to go with it.
I have seen guns that went through a fire inside a quality gun safe. Some of the guns didn't fair well. Plastic parts deformed and the finish was ruined. One way to prevent this is silicone treated gun socks. And I have also seen guns that were left in the gun safe after a fire that rusted. Why? The fire department hosed down the home. And either the seals on the gun safe let water seep in or it was condensation inside the safe. Again, use gun socks.
And as far as combinations, I highly recommend a traditional dial. Not digital. Digital does not last anywhere near what a dial type does. I have replaced many that have failed. And I have seen dial types that were almost 100 years old that still worked fine. However, if you have arthritis, have trouble remembering the dial sequence, or intend to use the safe for quick access, then get a digital combination. Just be aware that if it goes bad and the safe is closed, your looking at $300 and up just to get it opened. And list price on an S&G digital combination is $350.00 or so. $650 and up for repairs is nothing to take lightly. The dial type MAY need to be serviced every other year. That could cost $150 and up. But again it will last longer.