Check out Sturdy Gun Safes. They are custom built to your specs and can be configured similarly to a Liberty safe, but for typically less money. I got the smallest 60" tall model which was 19" wide and it weighed almost 800 lbs, so it's got some steel in it. The company also has some interesting videos on their site comparing their product to other safes.
Good luck with your search,
1965 Mustang convertible
347 Stroker with Holley Dominator EFI
Street or Track coil-over suspension