Sources for DIY Safe materials.
A few years back I designed an in-wall mirrored gun safe that was made from 20 AWG steel. This posed some problems that are hard to solve at your local big box lumber yard.
I planed on using one of our KR-S80Am Master/Slave lock systems so I had more than one locking point which is found on our store at www.gagesafeproducts.com .
The steel and mirror was easy for me to locally source, however I needed to find a heavy duty piano hinge, gun safe fabric and for a second project a pair of gas struts.
You will find a lot of companies that supply all sorts of piano hinges out there. Because I needed to screw half of the hinge to the box and spot weld the other half to the door frame and have it handle 80 pounds of mirror and steel it needed to be strong. The company that I selected and used was GUDEN Industrial Hardware.
As far as a gun safe fabric I went with POLYMAT. They offer different grades of matting along with color options.
For my other build I needed a pair of gas springs to take the wait off. As before I looked around and found a company called Gass Spring Shop at, www.Gasspringsshop.com. What was nice with this company was an estimator. You input your dimensions, weights ect. and they will tell you what gas spring will be best and where to mount the struts based on your inputted design. I also felt their pricing was fair. One piece of advice for you is make sure your weights are correct. I made the mistake of inputting an over estimated weight and now am the proud owner of a pair of gas struts that could be used to lift a Mac truck well not quite but you get the idea.
All of my projects use Gage Safe Products, KR-S80 series locks to secure them.
The in-wall project because it was built out of steel used a Master lock that was remotely mounted and two slave locks that did the locking of the mirrored door.
The second project only needed the Master lock and the Slave lock inside the wood frame in order to lock down the lid.
I hope this information is helpful to you and allows you to think and build outside of the box.