I started with a small safe and quickly regretted it. I bolted down and concealed it behind a false wall behind a small storage room under a flight of stairs. You need room for your stuff - but also for dessicant inside the safe. I left that one behind and got two Liberty gun safes 800 pounds each. I concealed these safes in a small room behind a false wall when i finished a new basement. When it was time to sell that house, the buyers and their home inspector never found the wall or room. The wall was knotty pine planks ship-lapped so it was not obvious that pulling on one plank would expose a hinged door. When the new buyers did their walk-through a few days before closing, their jaws dropped when I showed them the hidden room. They decided to buy one of the safes and I hired a safe moving company to move the other one to another place.
Don't bother with the lightweight lower quality warehouse club or department store safes. Visit a gun safe store showroom and talk to a professional. Get one size bigger that you think you need. Remember that high fire resistance reduces interior volume.