I'm presently going through the search for a gun safe. Do all the researching you can. Not all safes are created equal. Don't know your budget but to get a upper end, decent qlty safe you will need to spend in the range of $2k or more. Pay attention to the materials being used. Lower end safe may not have anything thicker than 12 ga steel being used. A fire ax can chop through 12 ga steel. Oh, many/most of the lower end models are being imported from China which is not an automatic condemnation but you do need to pay attention to materials and construction.
Depending upon where the safe will be located, 12 ga steel may be OK for sides but IMO never for the door. Need at least 1/4" and what if any additional steel is behind the face of the door in the lock area. Should be thick and heat treated and SST is desirable. Bolt the safe down to the floor. If they can't get it tipped over and pulled out from surrounding items, that will make entry harder.
Some kind of defroster is needed as a lot of newer safes the door isn't tight when closed. Moisture can move in/out with ease.
Oh, for the lock, I'm not a fan of the electronic models. Far too easy to over ride them. The real lock is an electric solenoid and if one get passed the outer steel one can jumper the 2 wires that operated the solenoid with a 9V battery and you're in.
Oh, one last thing. Find out the design for the lock/bolts. Some are such that a good blow to the entry bolt can cause failure. Same consideration if a hole is drilled in the side in-line with one of the door bolts. A rod and a good blow from a hammer can defeat the bolts and you're in like Flynn.
Good luck on your search and purchase.