I have a Liberty - it's ok for a RSC. But I think there are better options out there.
Take a look at
Sturdy Safes. They use a much thicker steel than Liberty. Ft Knox put out a video of some guys breaking into a Liberty in less than a minute with a pry-bar and some basic thieves tools.
If you want real security, take a look at
Brown safes. I could care less how the safe looks (I'm not going to have it in the living room). Their commercial safes are top notch and I think a good value.
As far as dehumidifiers - I use cat box crystals and fill several socks per safe. My safes are in the garage - a horrible place for safes and humidity - and I have not had problems with rust. The cat crystals are the same as the desiccant packs - just a heck of a lot cheaper.