It all depends on how much available space one has. If I had more room, I would add to what I have.
Now, I have one Winchester 800# safe rated for 24 long guns, pistols and assorted valuables... Almost filled... with twelve 1.25 inch locking bars, external hinges (of course) rated for 1400 degrees for 90 minutes. Local Fire House is seven minutes away...
No ammo stored in there, ever. For that, I have a Stack-On cabinet for ammo, loaded and unloaded magazines and supplies, accessories, etc. bolted to the wall studs from inside. Bolted on top of that is a Gunvault quick access box.
I've read that a circular saw with a carbide blade can go through the side of my safe in minutes... But it's my best defense. Open to suggestions on making it better....