What safe should I get?

As you have discovered, all of the safes have doors that are much heavier than the bodies of the safe. Yes, the doors are so heavy that when you open them, they want to tip forward onto you.

I remedied this issue by placing several bags of lead shot on the floors of my safes. It takes about 8 bags (25 pounds each). That also increases the weight of the safe by 200 pounds and would make it harder for thieves to carry it away.

I agree with nick on this one. I own 6 full sized gun safes and none of them are bolted to the floors. And I too line the bottoms with bags of lead shot. I feel that it's something that I can use for reloading in the future, so it sort of holds the value. And, it also increases the overall weight of the safe, making it much more difficult for would-be robbers to try to move.

Another you can do as an apartment dweller is simply find ways of hiding your guns. Most burglars are going to spend as little time as possible when they rob an apartment. So, something like a false wall inside a closet, or an old console TV that no one wants these days, can make for good places to hide some smaller guns.

I agree with nick too.

my safe is weighted down with bars of lead. I don't know how much it weighs now, but its hardly portable.

my safe is a little stack-on pistol safe, the bottom 1.5 inches is just lead blocks. I gave my safe some rubber feet so a burglar can't try & slide it off the cabinet I have it on. the only way to move the safe is to pick it up, I purposely made it so that you have to stoop down to open the safe, you'r in such an awkward position you can't pick it up.